cap medal for outstanding achievement in … filel aurÉats et p rix de 2009 la physique au canada /...

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rofessor Mandelis is a leading applied physicistand instrumentation scientist of internationalrenown in the broad area of applications of lasersin materials science and engineering; particularly

he is a pioneer in the development and shaping of diffu-sion-wave sciences and associated technologies, a familyof analytical techniques which include a rapidly growingrange of phenome-na, such as( p h o t o ) t h e r m a lwaves, photoa-coustics, photo-excited electroniccarrier waves anddiffuse photon den-sity waves.

P r o f e s s o rMandelis’ prolificand diverseresearch recordover the past 30years has beeninstrumental indefining the disci-pline of diffusionwaves as a unifiedscientific field,extending itsboundaries to anextraordinary rangeof applications andbringing aboutworldwide use andadoption of theanalytical tech-niques, theoreticalm e t h o d o l o g i e s ,ins t rumenta t ionand measurement technologies and inventions introducedby the Nominee. Based on documentation in internationalhigh-impact journal publications, proceedings of numer-ous multidisciplinary international conferences, books andedited volumes by the Nominee, review articles written byother scientists working in one or more of these fields andstandard Citation Index searches, Professor Mandelis’research consists of a remarkable number of outstandingcontributions to the science and engineering of diffusion

CAP MEDAL FOR OUTSTANDING ACHIEVEMENT IN

INDUSTRIAL AND APPLIED PHYSICS

LA MÉDAILLE DE L'ACP POUR DES RÉALISATIONSEXCEPTIONNELLES EN PHYSIQUE INDUSTRIELLE ET

APPLIQUÉE

Recipient of the 2009Medal / Récipiendairede la médaille de 2009:

Prof. AndreasMandelis

waves, of proven international impact. The extraordinari-ly diverse range of disciplines pioneered, co-introducedand/or developed by the winner of the 2009 CAP Medalfor Outstanding Achievements in Industrial and AppliedPhysics includes, but is not confined to, fundamentalphysics of linear and non-linear diffusion waves, with spe-cial focus on thermal waves; methodologies and devices

for thermophysicalproperty measure-ments in condensedand gaseous matterusing (photo)ther-mal waves and pho-toacoustics; opto-electronic dynamicand spectroscopictechniques basedon photo-excitedcarrier waves ins e m i c o n d u c t o r sand optical materi-als; sub-surfaceimaging of materi-als, photothermaldepth profilometryand inverse prob-lems; novel univer-sal signal genera-tion and detectiontechniques for usewith arbitrary non-destructive evalua-tion methods (ther-mal waves,acoustics, optics);combinations ofrigorous theoreticalapproaches and

PLa médaille de l'ACP pour desRéalisations Exceptionnellesen Physique Industrielle etAppliquée est décernée àAndreas Mandelis, Universitéde Toronto, pour ses travauxabondants et son impactfécond sur la science et legénie des ondes de diffusion.Il a été l’un des pionniersdans l’utilisation de tech-niques photoacoustiques etphotothermiques en pro-filométrie de la profondeur dediffusivité thermique et entomographie en coupe pourl’imagerie des défauts sous-jacents de substancesopaques. Il a fait de remar-quables contributions à laphysique tant appliquéequ’industrielle par la ces-sion/commercialisation con-tinue des produits de sarecherche fondamentale etappliquée auprès dessecteurs de l’industrie et dela santé

The CAP Medal forOutstanding Achievement inIndustrial and AppliedPhysics is awarded toAndreas Mandelis, Universityof Toronto, for his prolificworkd and seminal impact onthe science and engineeringof diffusion waves. He haspioneered the use of photoa-coustic and photothermaltechniques in thermal-diffu-sivity depth profilometry andcross-sectional slice tomog-raphy for sub-surface defectimaging in optically opaquematerials. He has made out-standing contributions toboth applied and industrialphysics through continuoustransfer/commercialization ofthe products of his funda-mental and applied researchto the industrial and healthsectorsversely-excited atmos-pheric carbon dioxide laseras well as his work in systemperformance modeling.

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fford

Sticky Note

This is an official electronic offprint of the CAP medal announcements published in Physics in Canada, Vol. 65 No. 3 (July-Sept. 2009), pp. 159-187. Copyright 2009, CAP/ACP All rights reserved/ Tous droits de reproduction réservés. F.M. Ford Managing Editor, PiC

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novel experimental configurations to shaping the fields ofbiothermophotonics and bioacoustophotonics, with imme-diate applications in optical, thermal and/or acoustic prop-erty measurements of hard and soft tissues, includingdepth-profilometric and depth-selective tissue imagingand dental caries diagnostics; hydrogen gas and environ-mental sensor devices; physics and measurements of non-radiative and optical properties of optically active solids;and photothermal diagnostics of thin films and surfaceengineered solids. Because of Professor Mandelis’ contri-butions, the biennial International Conferences on

Photoacoustic and Photothermal Phenomena (first con-vened in 1979 in Ames, IA, USA), the triennialInternational Workshop on Advances in Signal Processingfor Non-Destructive Evaluation of Materials, Quebec, andthe triennial NIST Conferences on ThermophysicalProperties (Boulder, CO, USA) feature structured themeareas in Diffusion Waves, Inverse Problems andBiothermophotonics since the 1990s.

Roman MaevUniversity of Windsor

I am very happy and honored to be the recipient of thisprestigious 2009 CAP Medal for OutstandingAchievement in Industrial and Applied Physics. It is a dis-tinct honor which I wish to share with the research team Irepresent, the many talented research associates, postdoc-toral fellows, graduate, undergraduate and high-schoolstudents who, through the years, have helped make theCenter for Advanced Diffusion-Wave Technologies of theUniversity of Toronto a unique and truly interdisciplinaryentity in the broadarea of diffusion-wave instrumenta-tion physics andtechnologies. It is aplace where manypeople work togeth-er with backgroundsspanning the spec-trum from con-densed matter physi-cists to chemists,mechanical and elec-tronic engineers, todentists, signal ana-lysts and imagingscientists.

It is also a distincthonor for me to havebeen nominated byProfessor RomanMaev, himself therecipient of the 2007Medal. I also wish tothank my colleagues around the world who supported mein this nomination.

Receiving this Medal means a great deal to me. It is theresult of the confluence of many factors, yet by no meansa one man’s act. I built a career on the very idea of the

pursuit and exploration of what is inherently curious, chal-lenging and interesting combined with what is useful tosociety: A good blend of science, engineering and entre-preneurship which we call “applied and industrialphysics”. I tend to think of “Applied Physics” as the sci-ence behind the engineering – the quantification of theexperiment and signal theory; and of “Industrial Physics”not as physics being done by industrial scientists, butrather as physics being done by any scientist dealing with

problems of indus-trial nature andinterest: these areby far the mostchallenging ones, Ifound, due to thenon-ideality andsheer variability ofindustrial materialsand processeswhose fundamentalproperties we study. At the University ofToronto I found fer-tile ground andample support todevelop mym e t h o d o l o g i e s ,because I was ableto find and recruitother, equally ambi-tious and very tal-ented young menand women, stu-dents and young

scientists who shared the passion. I am grateful to the CAPfor recognizing that Applied Physicists can be found evenin engineering departments. Its recognition of Applied andIndustrial Physics, and by extension, of Physics done inEngineering, as a legitimate physics profession will sure-

"It is a great honor forme to be awarded theCAP Medal forOutstandingAchievement inIndustrial and AppliedPhysics. As an AppliedPhysicist in anEngineering Faculty andDepartment, this Medalis testimony of how suc-cessful the Physics andEngineering communi-ties can be when theyinteract, complementand greatly enrich eachother."

« Je suis très honoré derecevoir la Médaille del’ACP pour contributionsexceptionnelles à laphysique industrielle etappliquée. Comme je leconstate à titre de physi-cien dans cette disciplineau sein d’une Faculté etd’un Département degénie, cette médailletémoigne à quel point lescollectivités de laphysique et du géniepeuvent connaître le suc-cès si elles interagissententre elles et si elles secomplètent et s’en-richissent beaucoupmutuellement. »

RESPONSE BY ANDREAS MANDELIS

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ly inspire a number of practitioners to excel in their cho-sen careers and (hopefully promptly!) join the CAP.Indeed, it will be flattering to my “pure physics” col-leagues to know that my students are keenly aware thatthey are doing science in engineering and they considerthemselves “special” and definitely more challenged thantheir “pure” engineering colleagues.

There is beauty in the common threads underlying the dis-ciplinary diversity afforded by instrumentation science. Itgave me the desire to share it with other CAP colleaguesin establishing the Division of Instrumentation andMeasurement Physics in 2000. The DIMP now closelycollaborates with the DIAP and the DMBP in a number of“hot” research areas in materials and advanced manufac-turing, in applied biophysics and the nanosciences. Thedesignation of this Medal as pertaining to combinedachievements in Industrial and Applied Physics is also ofcentral importance to me because the scientific efforts ofmy group at the cross-roads between applied and industri-al physics have resulted in two Toronto area spin-off com-panies, Photo-Thermal Diagnostics (PTD), and QuantumDental Technologies (QDT). PTD has developed laserphotothermal metal hardness metrology instrumentation,

the result of our theoretical and experimental depth-pro-filometry research in the regularized ill-posed thermo-physical inverse problem associated with harmonic para-bolic thermal-diffusion boundary-value problems (the so-called “thermal harmonic oscillator”). PTD has also devel-oped semiconductor recombination lifetime imagers forprocess quality control, based on diffuse photocarrier den-sity waves and the concept of “plasma harmonic oscilla-tor”. QDT has exploited mid-IR thermal (Planck black-body) and near-IR luminescence emissions from laser irra-diated teeth and their dependence on the degree of enam-el demineralization as sensitive predictors of early subsur-face caries. I want to acknowledge the decisive role of theOntario Centers of Excellence and the Center ofExcellence for Materials and Manufacturing, in particular,in co-funding these key areas of our research that led tothe emergence of the industrial spin-offs.

Last, but not least, I wish to acknowledge with gratitudethe love and understanding of my family, my wife Nancyand my two daughters, Alexandra and Nicole. Theydeserve a big “thank you” as this Medal would not havebeen possible without their unconditional love, supportand encouragement.


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2009 MEDALS AND AWARDS


Prof. Hong Guo

rofessor Hong Guo’s is a theoretical condensedmatter physicist with broad interests. His work hasimpacted nano- and mesoscopic physics, quantumtransport theory, and molecular electronics. He

has made pioneering contributions to the development oftheoretical formalism for the analysis of quantum trans-port in nanoelectronic systems. Indeed, the remarkableminiaturization of semiconductor microelectronics overthe past several decades has had a deep impact on the waywe live today and will continue to shape our lives. Owingto its profound eco-nomic, social andscientific implica-tions, the science ofvery small elec-tronic devices isnow a centraltheme of world-wide research.Hong Guo’s careerwork at McGill isin this excitingfield, and he andhis group havemade fundamental contributions to both fundamental the-ory and modeling.

The demands of nanoelectronic devices on theory are con-siderable: One needs a conceptual framework thatincludes elements of quantum physics, materials physics,non-equilibrium statistical physics, and atomic physics.Furthermore, applying this machinery to realistic many-body systems is a daunting task: Hong and his group roseto the challenge. Their work at McGill has resulted in asystematic and creative approach, unparalleled in its suc-cess. Guo and coworkers have devised this highly originaltheory by combining density functional theory (DFT) andnon-equilibrium Green’s functions (NEGF) formalism.

THE CAP-CRM PRIZE IN THEORETICAL AND

MATHEMATICAL PHYSICS

LE PRIX ACP-CRM DE PHYSIQUETHÉORIQUE ET MATHÉMATIQUE

These powerful techniques could then be put to work onthe analysis of nonlinear and non-equilibrium quantumtransport in nano-scale devices including all atomic micro-scopic details of the device structure. Up to this break-through, the modeling of non-equilibrium quantum trans-port had been a difficult problem that hindered progress innanoelectronics device theory and development. Guo’sNEGF-DFT approach is now being used by a large com-munity of researchers in nanotechnology and nanoelec-tronics, and has even become the scientific backbone of

commercial soft-ware. More recent-ly, Guo’s group hasdeveloped a treat-ment of non-equi-librium vertex cor-rection (NVC) thatsolves the difficultbut practicallyimportant problemof disorder averag-ing in non-equilib-rium quantumtransport theory.

Their NVC theory allows the quantitative analysis of real-istic nanoelectronic devices where some degree of disor-der is practically unavoidable.

Over the years, Professor Guo has also maintained scien-tific ties to the Chinese community worldwide. He is cur-rently an Honorary Professor in the Department ofPhysics, University of Hong Kong and Overseas Advisorto the Chinese Academy of Sciences. He is a member ofthe International Center for Quantum Structures (ICQS),of the Institute of Physics, of the Chinese Academy ofScience, and a member of the International Center forQuantum Design of Functional Materials (ICQD) at theChinese University of Science and Technology. He alsoholds visiting positions at Nanjing University, FudanUniversity, Sichuan University, and at Sichuan NormalUniversity. In the past, Hong also held visiting researchpositions at the Hong Kong University of Science andTechnology, at the Academia Sinica in Taiwan, and at theNational University of Singapore.

Professor Hong Guo, James McGill Professor at McGillUniversity, has contributed greatly to the field of theoreti-cal and computational condensed matter physics in

P

Le Prix ACP-CRM dephysique théorique et mathé-matique est décerné à HongGuo, Université McGill, pourses travaux novateurs sur lathéorie ab initio du transportdans les systèmes de taillenanométrique, en particulierpour la théorie des circuits oùle courant passe par desmolécules individuelles

The CAP-CRM Prize inTheoretical and MathmaticalPhysics is awarded to HongGuo, McGill University, hispioneering work on the ab ini-tio theory of transport innanoscale systems, includingthe theory of circuits in whichcurrent flows through mole-cules


Canada since he joined McGill University as an assistantprofessor in 1991. His work at all stages of his career hasbeen at the level of a scientific star, marked by originalityand significant impact. His research has been recognizedby a Killam Research Fellowship and by the BrockhouseMedal of the CAP and its Division of Condensed MatterPhysics. He is a Fellow of the Canadian Institute forAdvanced Research, and he has been elected Fellow of theAmerican Physical Society, and Fellow of the RoyalSociety of Canada.

Hong Guo has built a unique research program in Canadawith profound scientific impact and also with direct rele-vance to practical applications; Hong is a dynamo of newideas and has trained generations of graduate student andpostdoctoral fellows. This year’s CAP-CRM Prize inTheoretical and Mathematical Physics is rewarding anoutstanding individual.

Charles Gale, ChairMcGill University


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BJ – How did you get into physics?

HG – That is interesting, actually. My career … I think Ihave been somewhat lucky. Always good things happenedat the most critical time. I got into physics completely byaccident. Those were turbulent days in China. After highschool I was sent to a farm, very far from home. I was ateenager in those days, but everybody did that. You reallydidn’t feel … because everybody went. So I went to amountain and lived there for almost four years, three years Ithink, as a farmer. And then in 1976, the university startedto … somehow some universities came to our region to pickup some students. Iwas there already,more or less, fouryears so the localpeople thought that Ishould go to universi-ty. There was noexam and I didn’tknow what I wasgoing to do so I wasactually told to studyliterature. I said Idon’t want to studyliterature.

BJ – Why were you told to study literature?

HG – Because they just feel that anybody can study litera-ture. Anybody can study anything… But when the officialletter came, it said that I was in the physics department sothat is how I went to physics.

BJ – It wasn’t even your decision.

HG – Yeah, it wasn’t my decision. Then I wanted to studyelectrical engineering actually, but I never got a chance. SoI went to this university which is training high school teach-ers. It was a Normal University. But not the highest level.It was a provincial university, but it was a very good univer-sity.

BJ – What area of China?

HG – In Chandoung in Suchan province, in the southwestpart of China. That allowed me at least to return home.After four years I had forgotten everything from high schooland our high school, it was … it was turbulent years. Younever know where you were actually. Anyways I went touniversity and studied physics but this was very preciousbecause most people in my class never went to university.They never got a chance. I was very lucky.

BJ – Why were you selected?

HG – There wasno reason. Therewas a list of peoplewho came to thefarm and then thelocal governmentsays this guy hasbeen the longestthere so he gets thenext opportunity toreturn home orsomething. So I was

just picked… Before me a bunch of them went to work foroil fields. But then the next ten or so people went to univer-sity so I was very lucky.

BJ – Very random.

HG – Very random. But then I went to this place I studiedand we worked very hard. I did my undergrad in just twoyears. I finished very quickly. And then it turns out I amsupposed to become a high school teacher but my universi-ty is very kind and they try to keep young people and goodpeople so I was able to get a good job at the university. Theykept me as a teaching assistant. Just a little bit like our TAhere. In China in those days it was actually a job.

BJ – Actually a profession, right?

"I am extremely happyand honoured to benamed the recipient ofthe 2009 CAP-CRMPrize. I wish to thankCAP and CRM for thisgenerous recognition."

« Je suis extrêmementheureux et honoré de mevoir décerner le PrixACP-CRM de 2009. Jetiens à remercier l’ACP etle CRM de cettegénéreuse reconnais-sance. »

INTERVIEW WITH HONG GUO, JUNE 7, 2009, MONCTONNEW BRUNSWICK (BY B. JOÓS)


HG – It was a profession. Your job is to mark papers andthen take lab sessions and things like that. So I was there foranother one and one-half years doing this kind of work andthen China opened up. That was 1980. So when ProfessorTsung-Dao (T.D.) Lee, a famous Nobel prize winner [hewon the Nobel Prize in Physics in 1957, with C.N. Yang],went to China and said that we should take some students tothe US. So he set up this China/US examination programthat is a national program [CUSPEA (China-U.S. PhysicsExamination and Application)]. Anybody can write theexam. If you can write the exam and you can pass, youmight be able to be selected. So I was able to actually takethis exam in my city. My city is a big city in the southwestpart of China. So there is an examination centre there.Hundreds of people … a lot of people… I was one of thethree people in that exam, actually in my region, who passedthis exam.

BJ – So you were in the top three?

HG – I was very lucky. I know … we did poorly. Beforethat exam I have never even seen an English problem.Because in China we study in Chinese, so there are noEnglish books. Most of the problems I couldn’t do becauseI couldn’t understand one word. Somebody used somemeter and measured something. I don’t understand what isthis “meter” and what is this something. So a lot of prob-lems you couldn’t do. We were very poor in English inthose days. I managed because everybody did even worse.So basically I managed to pass the exam. So there wereabout 100 people that got selected and then we start to applyto the US … so that is how I went to the US actually, as agraduate student in 1981. I went to the University ofPittsburgh. I went to Pittsburgh also by accident because Iknew somebody who was also in my group. He got only oneoffer – from Pittsburgh – and so I went with him. So I knewsomebody. We went together. That’s all. Then I was verylucky. I worked with David Jasnow who is a tremendousteacher and he usually does not take many students. I wasthe only student when I was there. He had many postdocsbut picks students very carefully. But then he spent a lot oftime, every week I would go to his office.

BJ – So how did you distinguish yourself? You had takena year of courses, right?

HG – I wanted to work with him and then he said “I havea student, I don’t want to take any more students”. I was notable to join. So I joined an experimental group and did twoyears of experiments on atomic physics. So I did a mastersthesis in experimental atomic physics. After these twoyears, his student graduated and so I went to him again andso he was kind enough to take me.

BJ – So you really wanted to do theory?

HG – I wanted to look at theory. I did okay in experimentsbut I was a little bit lazy I think. Experiments frustrated me.You worked so hard and then … in the two years I probablyhad one month of taking data. The rest of the time was real-ly working with equipment. But still it was a great experi-

ence. That is why I work with experimentalists these days.They can talk in some language that I understand. Then Iwas able to join David and study statistical mechanics. Thisis something that has played an extremely important role inmy career in the end. Although now I do work which seemsto be not really related to statistical mechanics but actuallyit is ultimately related. That actually defined the path of mycareer I think. To realize how important non-equilibriumstatistical mechanics is. I will come back to this … A lotof people missed these opportunities. I think it is related tothis training in non-equilibrium statistical mechanics.

I graduated from David and had great fun there. He gaveme every week a stack of papers to read which had nothingto do with my research. In those days people sent him pre-prints.So basically he said “read this” and he explained it to me thenext week or something. So I spent hours reading thesethings which had nothing to do with my research. Whileother people were publishing papers, I was really readingthese useless papers, I thought. But then, after graduation, Isuddenly realized that I actually know much more thanmany of my peers. By reading these, somehow you have awide range of ideas and you understand what is going on outthere. So this was actually part of the training I realizedafterwards. I only published three papers in my PhD.

BJ – Three is okay. In those days especially..

HG – Two of them actually went to books, and they areimportant work, but actually the important thing I picked upis how to read different fields. I think that is very important.

BJ – and in the larger view …

HG – In the larger view of physics. What is happening,and how do you get into a new problem, and things like that.That prepared me very well I think. I felt in this sense thatmy own students actually read much less.

BJ – It is hard to make them read because they think somuch about the work they have to finish and the papers towrite …

HG – Exactly. People are much more conscious about thenumber of papers these days so the pressure is bigger. WhenI was doing my PhD in the 80s, how much you knew seemedto be valued very much. When I graduated I got a lot ofpostdoc offers. I think I got 15 offers from different coun-tries.

BJ – It was because of David …

HG – Yeah. David said you should not do this any more.You know, ε-expansions, Feynman diagrams… . Doingsomething very different would be good for you. So I wentto a group which does related things. This was Jim Gunton’sgroup. Actually he had a project of working on silicondevices, although he is a statistical mechanics person. Buthe had actually a collaboration with engineers, on surfacestructures on silicon and things like that. I found this was a


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group where I could talk to statistical people… It was inPhiladelphia. I found that I had made an absolutely won-derful decision. It was just the beginning of somethingcalled mesoscopic physics and so Jim said that he feels thisis a very important field. He doesn’t really know a lot ofthings but his grant came from the Office of Naval Research,doing this silicon work. You should do this. I got the free-dom to look for problems in there. Because of my back-ground, I think it was very successful. Very quickly wepicked up some nice problems and that is how I entered intothis sort of device work. I worked with engineers. Then Icame to McGill where I felt that I should continue on thismesoscopic physics, quantum sort of transport theory …

BJ – Why did you apply to McGill?

HG – That was another lucky thing. I was on a student visain the US. I was a foreign student. So one day my visarenewal was rejected. Then at a computational conferencein Princeton I met Martin Grant.Well, we met after the conference actually. So I said, “Doyou have a job in Canada? I have to get out of here by nextMarch”, or something, basically, because of immigration. Ihad a problem with my visa and so I was very lucky. Thenit was very lucky that they had a position, an opening. So Icame in 1989, first as a postdoc with Martin and then afterseveral years …

BJ – Twenty years ago.

HG – Yeah. I came to McGill. Then I got a faculty posi-tion and so I stayed. Then, after the faculty position, I wasthinking ‘where can I establish an independent research pro-gram?’. Very few people in Canada at that time actuallyworked on semiconductor nanostructures. People startedbut, theoretically at least, not a lot of people. There is NRC– big operation going on – but theoretically I felt that this …

BJ – George Kirczenov ?

HG – George Kirczenov. There are some scattered verygood people, but not really a very big program. I felt thatthis was a little bit of an empty space for me to play somegames. There was some very useful work to be done. So Istarted looking at these semiconductor systems by followingother peoples’ work. At the beginning you always do that …trying to understand certain transport phenomena. Veryquickly, starting in 1992 or something, I realized that all ofthis theory that we had been looking at since my postdoctimes are all built on somebody’s Hamiltonian. There is nomaterial science in there. It is effective mass, or free-elec-tron, or maybe a little bit better, parameterized potentials…I realized that, as these devices get smaller, if you have tenmore atoms or ten less atoms may make a difference at somepoint when it is small enough. So I felt that this is some-thing that we should be able to make progress on, and that…actually this comes back to statistical mechanics … that, youknow, in quantum transport theory, if you look at the bookson solid state physics, there is no statistical mechanics. It isequilibrium statistical mechanics. There is a Fermi-Diracdistribution and that is it. Basically you start with a

Hamiltonian … people are focused on the Hamiltonian –how do you get a better Hamiltonian is the emphasis: cal-culating more complicated potentials by more sophisticatedtechniques. But still, it is working on Hamiltonian. So onceyou have the Hamiltonian … actually I realized that whatyou have is energy levels. You want to build a densitymatrix and you have to put electrons on each of these ener-gy levels and that is statistics. How many electrons you putthere, what distribution do you follow? If you have spin-degeneracy, you put two electrons per energy level. But ifyou have a non-equilibrium situation in some way, you haveelectric current flowing through … you are not so surewhether you can put two. So the Hamiltonian is only part ofthe story. You have to have statistical mechanics there. SoI realized we must have a method which takes this quantumstatistical physics and the Hamiltonian, which is the materi-al physics, and the quantum transport theory … how do youcombine them together? I realized this reasonably early. Inthe early 90s we started to build these different tool boxes oneach of these disciplines. We were not so sure whether itcould be successful. We didn’t know but we tried basically.Then, after many years, we finally … we went to many dif-ferent wrong directions, but in the end we figured out a par-ticular approach which allows us to take these three intoequal footing; one formula that combines them together. Itis a practical theory because you can solve a thousandatoms. We decided to use the Keldysh nonequilibriumGreens function which allows us to build this density matrixfrom density functional theory.

That was after a long time. Along the way, of course, wepublished many different things, but this main direction Isaw reasonably clearly for quite some time and I thinkaround 2000. Actually I had a brilliant student who joinedmy group in 1997, Jeremy Taylor, and this is from this place– from Acadia – he did undergraduate work. He is a brilliantstudent. So he actually came and I had a very brilliant post-doc at that time, Kousodos Moudos who actually had abackground in statistical mechanics and he was in my group.We basically formulated this possibility and Jeremy Taylor’sthesis was to develop this computational tool. He was ableto actually do that in 2000. So this paper is cited like 400times now (Taylor, Guo, Wang, Physical Review BJ Vol. 63,245407 (2001), but before that there were many, many stu-dents who played … and we built up this machinery up tothis point and then we were very lucky to have him. SoTaylor, actually, he graduated from my group and went toEurope because his wife lives in Denmark. So this workreally took off and afterwards, from 2000 to now, of coursethis basically established some kind of reasonable … it’sstill approximate of course … you cannot solve this kind ofproblem exactly … but a reasonable approach. A lot of peo-ple follow this …

Industry is interested in this because their problems requirethis kind of tool now. We were funded by a semiconductorresearch corporation in the US, chip makers. They wantedto understand, for example, interconnects. You have kilo-meters of copper wires and chip which connects differentdevices but is, let’s say, 70 nanometer thick wires and thenyou have very thin copper wires to which resistivity increas-


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es due to surface Raleigh scattering. As the resistance goesup, you dissipate more heat and that kills the operation. Sobasically there was a very major problem facing the ITindustry chip makers, which is how do you reduce intercon-nect dissipation. We have been funded for five yearsalready doing this kind of work.

BJ – But interfaces / interconnects are dirty.

HG – Yes, so that is why you have to look at these atomicsystems. Because with the atomic model you can actuallybuild the wire with atoms and they don’t have to be perfect,you can have different structures. You have to do disorderaveraging of your results, and so when you have atomic cal-culations, if you have to do disorder averaging by calculat-ing a million kinds of regions, that becomes impossible. Sohow do you deal with this? You have to derive a formulawhich is averaged already automatically and then you calcu-late once. So this involves many-body theory. We devel-oped these kinds of tools called vertex correction to analyzethis, compute the average automatically and make it calcu-lable. That was another student of mine who did this lastyear and so now we can do doping, you know a lot of prob-lems… So this is very useful. Basically, along these lineswe have been looking at many, I think, rather importantproblems in electronic device physics. We are funded byindustry and so that means industry people – engineers –they have incredibly difficult problems, I think. We cantouch a little bit. I think that this formalism, this way ofgoing, so, for example, this particular kind of technique den-sity functional coupled with Keldysh Green function for-malism is picked up by engineers. They do this also now inthe device field.

BJ – You make it friendly enough …

HG – It is not less friendly … so that is why we are tryingto actually commercialize this.

BJ – Into a black box?

HG – To make a very user-friendly thing, you know. Ihave people who started up some company to do this. It’sthere. We also let people use, for free actually, if they havethe time to hack the difficult part of the mathematics and allthat…This is a very rich field. There is a lot of physics. Wehave not really touched strongly correlated electrons yet butthere are phenomena which already show up in the measure-ments, that, in some of the devices, especially in some oxy-des…

BJ – It is not just single electrons?

HG – Single electron is not good enough and that is a verydifficult direction, but you have to do it because there are,you know, like this MRAM, this magnesium oxide, sand-wiched between iron oxides. There is actually a strong cor-relation there so you have to worry about these kinds ofthings. These kinds of things will take us to the next step inthe future, I think. I have not really talked about high fre-

quency, you know. You want to calculate the speed of thesedevices. This brings us really far out of equilibrium.

BJ – So you have your work cut out for the future?

HG – We are now starting to write theoretical papers. Howdo you deal with these theoretical issues but then I think wehave to launch into trying to understand some of this fromatomic point of view so we can make real predictions. Wemade many predictions, I mean, people measure and thenyou find agreements. It is very satisfying. It is very nice.

BJ – Okay. You are doing very successfully and also youseem very much at ease with what you are doing. You justwork hard and you like it and things work out, but how doyou view your role at McGill – as a university professor?

HG – I remember years ago when I just came to McGill, Ijust went to some lab. I forget – IBM or somewhere – togive a talk. I gave my best talk. No (?) sophisticated theo-ry….. That gave me a very big eye opener. I realized that,actually, theoretical physics can be extremely useful andactually the engineers want it. I go to these grant reviewmeetings in the US with industry people (Intel, HP,…). Theysit with you and say ‘can you do this?’, ‘can you do that?’.There is a lot of interest in physics problems that reallyaffect engineering at this moment. So it’s a wonderful time.The problem is that theoretical people usually, like me in thepast, think calculating is not interesting… who cares … wedon’t do that. It is not going to generate big profile papers.Actually that is not true. If you can solve this interconnectproblem that is very important …

BJ – Yes, but the nano world is a lot more exciting than …

HG – So now we do this problem which looks very mun-dane from a theoretical point of view, but actually it is veryhot because you have extremely little data there. If youdon’t understand it, you can’t publish. You can’t really saywhatever you like, you really have to be right and this kindof works gets a lot of attention because once you make aprediction there are engineers who are measuring it. So it isvery tough actually and much more interesting than publish-ing purely theoretical papers, in my view.

BJ – So, you have evolved into somebody who finds hismotivation in solving practical problems.

HG – I have found it is much harder but much morerewarding because you can see that people can use yourresults. It is fantastic. You get feedback right away. Theseare real problems. This other … university professor … Ithink for students we, in the past, especially in these reallytheoretical places, people will value different things, butnow I think we should change. We should basically, if it isgood science, whether it is applied science or it is reallypurely theoretical science, it is good science, right?

BJ – Each field had its phase: a phase where you have todevelop the theory and then, once you have it, you have to


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see what you can do with it. I mean there is a differentmaturity, I guess, in the field.

HG – Every different people we can accommodate. But ifyou start to do this, it is very useful … to apply physicsproblems. I find students have more avenues to go on. Theycan get hired at companies or as university professors, or atnational labs, etc. It is much more versatile. Mind you,actually, these problems that we are trying to solve are actu-ally quite difficult. Sometimes we get discouraged also, youknow. But there is a very big push. All of this … actuallyit is ICP, actually. NSERC person mentioned it. The workwe do this is quite relevant actually. Technology. So thisis…

BJ – Yes, so you fit into NSERC’s mandate.

HG – What I learned doing this research, is that theoreticalphysics can be very useful if one cares to apply it.

BJ – Yeah, that is the general perception … We are notdoing it just for the fun. I mean …you have to have the feel-ing that some day it is going to be used for practical purpos-es.

HG – The thing is that this “some day” is actually now inmy field. These engineers, they are extremely good. I workwith them. I have found that they are very good.

BJ – Even if they don’t know quantum mechanics?

HG – Even if they don’t know quantum. They have anincredible intuition that we don’t have. They can guess andget it almost right, but the thing is that now it is down to thisregion that to guess is just not good enough any more so youneed this … I think that working with them, we will be ableto solve some of this. There is this very big industry outthere called electronic design automation which is a bigmulti billion dollar industry which has no tools at themoment.

BJ – These are mostly American companies …

HG – These are dominated by American companies, butthis big industry is trying to do design automation and theyneed parameters of devices. Now it is by measurements, butmeasurement is getting very difficult to do. Missing a fewatoms can make a big difference. That is difficult to para-meterize. This type of theoretical physics can be very use-ful for them. I can see that the modeling simulation, or the-oretical tool set, will change.

BJ – These devices that you are working on. They aremeant for what? Computers?

HG – I was most interested in these computer devices.

BJ – This is to improve chips?

HG – Silicon devices. Of course, in nano, you use differ-ent materials. In the entire computer technology, no more

than 15 different atoms have been used. But actually, if yougo to nano, there are many more different atoms. So thereis a lot of science that still has to be done. By the way, wealso work on magnetic memory type problems.

BJ – Storage?

HG – Not storage but mostly on where we register ourmemories? Hopefully we can replace our d-rams.

BJ – Oh, the live memories

HG – With other kinds of memories. Non volatile memo-ry code. D-rams and s-rams are made of transistors so if youturn off the electricity, your memory is gone and you haveto reboot but if you use this flash memory, or some othermemory, you see you turn on/turn off, your memory is stillthere.

BJ – Because the atoms are in spin configurations.

HG – Or something. So … but how do you make this fastenough, integrated enough, and what is the mechanismbehind this kind of memory. There is a lot of science to beresolved.

BJ – This is for miniaturization.

HG – Yes,, and we also work on new things like bio sen-sors. You can have these nano scope sensors which cansense femto- or something very tiny. Many orders of mag-nitude more sensitive than chemical sensors so they are …it is very interesting … it is a transport problem across thecurrent. Something docks, current changes, so it is a trans-port problem. We also work on photovoltaic systems. Thisis for photo current generation …

BJ – This is a light interaction.

HG – Light interaction. When any electron goes you havea transport problem with photoelectric current in this com-plicated material. Usually …

BJ – So the light excites the electron and you try to followthe electron in the device

HG – … p-n junction … so you can separate the positivewith negative charges. That is how the photo cell works. Sonow we work with engineers on things like nitrite, atoms innitrite. This is kind of new materials. Not really new, butnewer materials. This kind of atomic calculation is also veryuseful. So this is … all the sensors, all the detection tech-niques, need current. So when you have a current for use ina nano system, that’s where we do our research.

BJ – OK, very good. I think we have enough material!

HG – … I have not even touched on the structural calcu-lations. We talked about the current. You know nano sys-tems, there is a huge force and the structural change is very


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complicated, and this is something that is another two hoursof interview. ..I like this kind of thing very much – appliedphysics problems. I think it is very interesting.

BJ – It gives you a feeling of accomplishment.

HG – Also, more than that. Some times we are wrong, youknow, when we do something, because it is so complicated.

BJ – So the details matter. When you get to the nano, thedetails matter.

HG – You can really see that a few extra atoms make allthe difference. Many giant physicist, they made all of this,density functional theory possible. But what we really didis pick up the useful stuff and combine it together. That iswhat we did. So our innovation is not really to invent thiscomplicated theory but to use them in some wise way. Wecombined each of these big fields so that we actually knowhow to solve our problems. So I think at this moment, thetechnique and the theoretical formalism we developed nowbecomes the mainstream. Everybody uses these kinds ofthings. More people use it, you can get more criticism. Youget more improvement. People find more problems andthen these problems are being solved at the technical level.So the field advances.

BJ – You are not a big group person. You are yourself, andsome students and postdocs. You do the work yourself. Youdon’t delegate …

HG – I delegate a lot, but I have to know the details. Thatis one problem that I felt, in Canada, we have to find a wayto solve. In the old days, when we were doing research, wewould do one problem, we would move on to the next prob-lem, and so the continuity of the groups was not that impor-tant. But now we have developed this very complicatedcourse, over the span of ten years, and yet I have no stabili-ty in the group because my students graduate, my postdocsleave. If I don’t know every bit of detail, this science is lost.It is very hard for a group like mine to manage actually,because we have several different, very complicated, for-malisms. Many of this coding and details are done by vari-ous different people. You only have 24 hours. I would getlost. I felt that there should be a mechanism, like in anexperimental lab. When you have a big lab, you have atechnician who takes care of the data. In theoretical groups,we don’t have this possibility and so basically now I spendalmost all my time trying to figure out why this ð is there orsomething.

BJ – That’s almost technical work.

HG – Very technical work. To the bottom. It is very hardfor this reason. That is actually why, if you see the impor-tant software in scientific software, they were mostly devel-oped in Europe. I don’t know any in Canada.

BJ – Because they put the resources for technical help.

HG – In Europe, in a university, a professor can havesmaller professors. They have a hierarchy. They can havea continuity in research

BJ – with some stability in it.

HG – Here I have no stability. Suppose tomorrow, mymost important postdoc finds a job. I have lost some veryimportant postdocs before and I have been in limbo. It tooka lot of effort to get it back.

BJ – That is what people say – some things should bedone in research labs, and some things in university. A ques-tion of keeping a sort of memory of the accomplishments inthe system.

HG – But in my university we have the advantage of manyyoung students. I think, if there are things like this, to sup-port this kind of … not a lot of people are using this butthere are some of us who are really needing it. So what I didbasically now is I found private funding and we started acompany up there and their role is to develop the softwareand maintain it. But this takes a lot of your time away. Ireally wish we had some kind of support, like a technician,for big computational groups. Not just computational … wealso do a lot of analytical work, right. So there is a lot ofexpertise.

BJ – We should fund it. The university cannot becausethe university has money for teaching …

HG – But the university has money for technicians forexperimental labs. So it has been accepted by the commu-nity. But if you say a computational group wants a techni-cian, people laugh you out of the door. They will never besuccessful. There is no mechanism. But in Europe that isnot the case. That is why there are so many fantastic codedeveloping work. Very famous ones. They have made ahuge impact. But here we have very little, so it is difficult.So I have been trying to do this through CIAR, you know wehave some other funding from them that helps us a lot, butstill the scale is not large enough.

BJ – No, but the university style system of research is notmeant for these huge projects … you are right, there issomething missing there.

HG – You know, we manage. I have quite a few postdocs.

BJ – I don’t know what happens if you are out of the sys-tem. Someone has to take it up …

HG – My problem is that if some of the key people leaveand I don’t know what they did, then I am dead basically, orthis work is lost – really lost.

BJ – It is a challenge, yes. Thank you for your time.


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a compétition entre différents types d’interactionsest courante dans le monde physique. C’est undéfi intellectuel de haut niveau avec des exemplesd’applications dans des domaines aussi différents

que les architectures d’ordinateur et l’économie. Dans lesaimants frustrés, un spin donné reçoit des signaux contra-dictoires de ses voisins et, globalement, l’énergie du fon-damental est diffi-cile à trouver oun’est peut-êtremême pas unique.Ces systèmes sontdes modèles utilespour des matériauxplus familierscomme les verres,des matériauxsolides où lesatomes sonta r r a n g é sirrégulièrement,plutôt que de for-mer un réseaucristallin. La frus-tration dans lesaimants peut seproduire à cause dudésordre ou à causede la géométrie. Michel Gingras hasmade seminal con-tributions to bothareas of magneticfrustration by dis-order and magnetic frustration by geometry. MichelGingras holds an MSc from Laval University, a PhD fromUBC, a Tier I Canada Research Chair at University ofWaterloo and is a member of the Quantum Materials pro-gram of the Canadian Institute of Advanced Research. Hehas received in 2001 the Herzberg Medal of the CanadianAssociation of Physicists, the NSERC Steacie Fellowshipin 2003 and numerous other awards.

Although the general topic of frustrated magnetism hasbeen around for at least 40 years, Michel is considered ashaving definitely solved the problem in at least onefamous case of geometrical frustration, that of spin ice, achallenge with clear experimental manifestations in


Prof. MichelGingras

pyrochlore compounds. As a first simple model for thesecompounds one usually considers Ising spins residing oncorner-sharing tetrahedra with spins fixed along the localquantization axis, the <111> cubic axes, which coincidewith the lines connecting each tetrahedral vertex to thecenter. Every tetrahedral cell must have two spins pointingin and two pointing out, in order to minimize the energy.

There is a largeamount of zerot e m p e r a t u r eentropy in the sim-ple classical model,analog to the icemodel of Pauling. It is now generallyaccepted world-wide that MichelGingras is the sci-entist that made thekey contributionsin elucidating themicroscopic originof the spin ice phe-nomenon as arisingfrom the unexpect-ed observation thatlong-range magnet-ic dipolar interac-tions are to a verylarge extend "self-screened" in highlyfrustrated lattices. His research hasresolved many keyissues concerning

the spin-ice phenomenon. I will simply list the main ques-tions that had to be addressed without going into details.

LLa Médaille Brockhouse estdécernée à Michel Gingras,Université de Waterloo, pourses contributions originales àla description des systèmesdésordonnés aléatoires etdes systèmes magnétiquesgéométriquement frustrés àl'aide de la mécanique statis-tique. Le Dr Gingras est dansce domaine un chef de filemondial et l’auteur d’un éven-tail remarquable de publica-tions. Ses travaux ont servi(comme l’a affirmé le DrThomas Rosenbaum, J.T.Wilson Distinguished ServiceProfessor, Université deChicago) « à donner àl’ensemble de la collectivitéune nouvelle perspective surla manière dont le désordrelocal et la frustration peuventêtre reliés à une réponsemacroscopique de la matière»

The CAP/DCMMP BrockhouseMedal is awarded to MichelGingras, University ofWaterloo, for his seminal con-tributions to the statisticalmechanics description of ran-dom disordered systems andgeometrically frustrated mag-netic systems. Dr. Gingras isan internationally recognizedleader in this field with anoutstanding publicationrecord whose work hasserved (quoting Dr. ThomasRosenbaum, J.T. WilsonDistinguished ServiceProfessor, University ofChicago) “to point the com-munity as a whole to a newperspective on how local dis-order and frustration can beconnected to a material’smacroscopic response”

THE CAP/DCMMP BROCKHOUSE MEDAL(FOR OUTSTANDING EXPERIMENTAL OR THEORETICAL CONTRIBUTIONS TO CONDENSED MATTER AND MATERIALS PHYSICS)

LA MÉDAILLE ACP/DPMCM BROCKHOUSE(POUR L'EXCELLENCE DANS LE DOMAINE DE LA RECHERCHE THÉORIQUE OU

EXPÉRIMENTALE EN PHYSIQUE DE LA MATIÈRE CONDENSÉE ET DES MATÉRIAUX)



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S2009 MEDALS - BROCKHOUSE (GINGRAS)

A) Are dipolar interactions compatible with spin icebehavior? -- Michel’s research has answered this questionin the affirmative. Moreover den Hertog and Gingraswere able to account quantitatively for the specific heatdata of Ramirez et al on Dy2Ti2O7 .

B) Are Ho2Ti2O7 and Dy2Ti2O7 on par in terms of spinice phenomenology? -- After identifying the key role ofthe large hyperfine interaction of the Ho ion in the exper-imental results, the effect was taken into account and leadto the first paper demonstrating directly the ice-like cor-relations present in a spin ice material.

C) Why do long-range dipolar interactions fail to destroyspin ice behavior? -- This is where Gingras and collabo-rators elucidated in full detail the phenomenon of self-screening in dipolar systems.

D) How is the Third Law of Thermodynamic Saved inDipolar Spin Ice? -- Since dipolar screening is not exact indipolar spin ice, Gingras and collaborators were able todemonstrate that from a statistical mechanics point ofview, dipolar spin ice does possess a true spontaneouslybroken symmetry transition at much lower temperaturecompared to where the maximum of the specific heatoccurs. This paper precisely clarified what the spin-icestate in real systems must be: a collective paramagneticstate where local correlations develop at a temperature thatis of the order of the Curie-Weiss temperature, and wherea large amount of entropy (Pauling's value!) is retainedthrough correlation effects as the temperature is reduced,but where long-range order via a first order transition (andwith a latent heat more or less equal to Pauling's value)only occurs at much lower temperature due to the screen-ing of the dipolar interactions).

E) Spin Ice in a Magnetic Field

G) Emergence and refrustration in spin ice

Michel has shown that the seeming emergence of compos-ite spin clusters and their associated scattering pattern isinstead an indicator of fine-tuning of ancillary correlationswithin a strongly correlated state. With this work, the pro-gram of understanding all the equilibrium thermodynamicproperties of spin ice materials is seemingly complete.

This groundbreaking work was carried out with much per-severance, attention to detail, numerical virtuosity andphysical insight. Dr. Gingras is also one of the rare theo-rists who is willing to get into the trenches with experi-mentalists to work out a detailed understanding of experi-mental data. This willingness to interface with experi-ments is abundantly evidenced by his publication recordthat shows a large number of high profile experimentalpublications on which he is a coauthor.

Michel Gingras’ scientific accomplishments have beenparalleled by a generous support of the community,notably through his leadership in the initiation of theHighly Frustrated Magnetism conference series. Since itsestablishment, in which he played a key role, this hasgrown to a truly international event for the exchange ofdata and ideas, and for collaboration.

Félicitations à Michel Gingras pour cette reconnaissancebien méritée.

André-Marie TremblayUniversité de Sherbrooke

BJ - As-tu des objections si nous faisions l'interviewen français ?

MG - Non, j'avais perdu beaucoup mon français. Il y acinq, j'avais un étudiant au doctorat qui était un français enco-supervision avec quelqu'un en France. Il m'a dit :“écoute, ça va être clair, on ne parle pas en anglais, c'estclair qu'il faut que tu practiques ton français”. C'est revenuassez vite.

BJ - Alors, n'étais-tu pas de la génération de RaymondLaflamme à Laval ?

MG - Exactement la même - Même année (1983). J'aifait deux années de maîtrise à Laval.

BJ - Avec qui ?

MG - Roberge en Optique.

BJ - Ensuite tu es allé en UBC.

MG - Oui.

BJ - Puis tu t'es retrouvé avec Birger Bergersen.

MG - C'est ça.

BJ - C'est comme ça que je t'ai connu -

MG - En premier, j'avais pensé faire la physique desplasmas puis j'ai changé d'idée - j'ai parlé avecWalter Hardy. J'ai passé 6 mois dans le lab deWalter Hardy. J'ai découvert que la physique des bassestempératures c'était trop compliqué pour moi.

ENTREVUE AVEC MICHEL GINGRAS, LE 9 JUIN, 2009,MONCTON NOUVEAU-BRUNSWICK (PAR B. JOÓS)


BJ - Tu étais avec Birger Bergersen. Tu n'as pas com-mencé avec le magnétisme avec Birger B. ?

MG - Non, des cristaux liquides, et des verres orienta-tionnels. Tu te souviens de Zoltán Rácz ?

BJ - Bien sûr, Zoltan Rácz, c'était un hongrois, uncompatriote.

MG - Oui. C'est comme cela que j'ai dévié vers lamécanique statis-tique parce qu'ilenseignait le cours demécanique statis-tique à UBC - alorsj'adorais ça - alors j'aiété le voir parce queje ne savais pas qu'ilétait en visite pen-dant 1 an j'espéraisfaire un doctorat aveclui - il m'a dit “nonnon non, ça marcherapas, parce que jerepars dans 6 mois” -c'est lui qui m'avaitmis en contact avecBirger.

BJ - C'était desbons amis, Zoltan,Mike Plischke etBirger Bergersen.

MG - Exactement. En fait je suis resté en contact avecZoltan.

BJ - Ta thèse était sur les cristaux liquides.

MG - Oui c'est ça - puis j'avais fait quelques calculsavec Zoltan qui se sont ramassés en fin de thèse sur lesinstabilités dans la croissance des gouttelettes (viscous fin-gering). Après mon doctorat je suis allé à Paris, c'est à cemoment-là que le problème des verres de vortex étaitvraiment à la mode. Je suis tombé sur le premier papier (iln'y avait pas encore d'ArXiv, cela n'existait pas encore).J'étais à l'Ecole Normale, ils recevaient des preprint departout. Il y avait un preprint de David Huse sur la pre-mière simulation sur les verres de vortex. J'ai dit : ah! Çaressemble beaucoup à ce qui m'a intéressé au doctoratdonc je me suis mis là-dessus aux verres de vortex. Puisquand j'ai fini à Paris, je suis allé à TRIUMF - je faisaisque commencer - je devais être là depuis un mois peut-êtrepuis Robert Kiefl….est arrivé puis il a mis une propositionde recherche de μSR sur mon bureau - puis il dit qu'il allaitcommencer à travailler avec Bruce Gaulin sur les sys-tèmes frustrés en présence de muons et neutrons, alors çava t'intéresser.

BJ - C'est lui qui t'avait engagé ?

MG - Non, non, c'est le labo qui m'avait engagé.

BJ - Les compétitions ouvertes pour les soutiensthéoriques ?

MG - Exactement - il y avait le “token theorist” poursupporter l'effort en muons alors à tous les deux trois ansils remplaçaient ces postes qui n'avaient pas vraiment de

personnel perma-nent à part peut-être deux. C'étaitc o m p l è t e m e n tlibre, tu pouvaisfaire ce que tuvoulais. L'idéed'interagir avec desexpérimentateursm'intéressait, etcela m'a lancé dansce domaine.

BJ - Et tu n'aspas démordé ?

MG - Je n'ai pasdémordé non, pasbeaucoup en fait,depuis ce temps-làj'ai quelquespapiers sur les

cristaux liquides et le modèle de Hubbard et mais surtoutsur les systèmes frustrés.

BJ - Utilisant des méthodes surtout numériques ouchamps moyens ?

MG - On a fait des ansatz, des calculs de renormalisa-tion, tout ce qui marche, tout ce qui peut marcher en fait.Tout ce qu'on a fait était vraiment très motivé par les prob-lèmes expérimentaux. On voulait utiliser la méthode quipourrait expliquer l'expérience, je ne suis pas vraimentintéressé à utiliser une méthode pour trouver le problème.

BJ - Donc tu as toujours travaillé depuis TRIUMFétroitement avec des expérimentateurs.

MG - Etroitement ? Oui, en collaboration, en fait, c'est“on and off”, mais ça toujours été très motivé par ce qui sepasse du côté expérimental.

BJ - Résoudre des vrais systèmes ?

MG - Des vrais problèmes, des vrais systèmes. Il y a unde nos papiers qui va apparaître. sous peu. J'avais un étu-diant qui voulait faire vraiment du magnétisme quantiqueet je n'avais aucune expérience donc je me suis dit qu'on


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MÉDAILLES 2009 - BROCKHOUSE (GINGRAS)

"I am most honoured tohave been awarded the2009 Brockhouse Medaland to be included intothis group of celebratedcondensed matter physi-cists. I take this oppor-tunity to thank my stu-dents, post-docs andexperimental colleaguesfor their many key con-tributions to theresearch projects thatled to this award."

« Je suis très honoré deme voir décerner laMédaille Brockhouse2009 et d’être inclus dansce groupe des physi-ciens célèbres de lamatière condensée. Jeprofite de l’occasionpour remercier mes étu-diants, les attachéssupérieurs de rechercheet mes collègues expéri-mentateurs de leursnombreuses contribu-tions clés aux projets derecherche qui ont mené àce prix. »


allait commencer dès le départ on va regarder le modèle deHubbard. Ce qui nous a motivé c'était des mesures de neu-trons inélastiques. A la fin on a fitté des dispersions inélas-tiques de neutrons. C'était intéressant, c'est toujoursintéressant de commencer sur un truc où on n'a jamais rienfait. On est un peu naïf, on commence puis on ne sait pasce que les autres ont fait. C'est une bonne chose, pour lesmodèles de Hubbard et les haut-Tc, si on commençait àlire ce qui a été fait on ne ferait peut-être rien….

BJ - En effet, c'est une littérature énorme qui est con-tradictoire ...

MG - C'est bien, d'être au Canada, cela m'a servi beau-coup, parce que quand on a commencé ce projet-là, je mesuis mis en contact avec André-Marie Tremblay qui est unexpert. Lui déjà il savait quel problème regarder … si onétait au Canada dans un système qui était beaucoup moinscohérent, plus compétitif ça aurait été plus difficile de semettre en contact. André-Marie a vraiment aidé beau-coup …

BJ - Louis Taillefer avait aussi insisté sur le fait qu'il yavait beaucoup de collégialité dans la communauté dessystèmes hautement corrélés au Canada.

MG - Je crois que c'est vrai.

BJ - Ce n'est pas une compétition, c'est plutôt unecoopération.

MG - Oui, si on veut travailler dans ce mode la, c'estpossible.

BJ - Alors donc pour toi c'était un jeu, ces systèmesfrustrés. Ils sont très fascinants parce que la richesse estétonnante mais quand même ce sont des systèmes durs àvendre parce ce qu'ils sont plutôt d'intérêt intellectuel quepratique.

MG - Oui, c'est vrai, mais, c'est toujours la même chose: il y a des avenues qui se développent auxquels tu ne t'at-tends pas, par exemple depuis quelques années la décou-verte de ces nouveaux systèmes qui s'appellent les sys-tèmes multi-ferroiques qui ont à la fois un ordre ferro-électrique, et un ordre magnétique, et pour avoir un ordreferro-électrique il faut que la symétrie d'inversion soitbrisée. C'est naturellement les systèmes frustrés où sedéveloppent des ordres spirales qui sont des porteurs deces genres de symétrie brisée. La plupart de ces systèmesmulti-ferroiques qui ont été découverts sont des systèmesmagnétiquement frustrés. L'ordre magnétique dans cessystèmes est autour du 50-75 K. En principe, il n' y-a rienqui empêche que certains de ces systèmes là existeraient àla température ambiante alors il y a beaucoup d'effort àavoir des systèmes où tu contrôles de façon magnétique etélectrique les spins et l'ordre ferroélectrique dont les appli-cations de ces systèmes seraient par exemple en spintron-

ique, sur des genres de valves magnétiques, des valves despin. Ce n'est pas exactement les problèmes que j'aiétudiés mais quand même il y a la notion que tu peuxtransposer les effets de frustrations à des phénomènes quivont peut-être éventuellement donner lieu à des applica-tions. La multi-ferro-electricité, c'est vraiment très à lamode …

BJ - Donc tu as beaucoup de succès et puis, je supposec'est parce que tu arrives à expliquer ou, satisfaire lesexpérimentateurs que ce qui apparaît pour eux commeétant un système insoluble a une explication.

MG - C'est vraiment le truc que je trouve le plus intéres-sant dans mon travail. Je respecte aussi beaucoup lesexpérimentateurs qui s'engagent dans un vrai projetexpérimental c'est un truc qui demande beaucoup d'effort.Donc, si des experimentateurs sont intéressés à ce que l'onfait coté théorique, je trouve ça souvent motivant. Un desprogrammes de recherche présentement est d'essayer detrouver des systèmes fortement frustrés qui sontmétalliques avec des spin ½ “en proximité” dans unephase isolante, et de voir quel genre de supraconductivitéqui peut en émerger. Somme toute, il y a un intérêt assezfort envers les systèmes frustrés. Par exemple le Japon aun réseau sur les systèmes frustrés avec un budget dequelques millions de dollars de recherche sur cinq ans.L'Europe au complet a un réseau qui est financé par laFondation scientifique européenne qui regroupe les gensde 15-20 pays qui travaillent sur les systèmes frustrés.

BJ - C'est que dans ces systèmes il y a un potentielpour de nouveaux phénomènes ?

MG - Oui, il y a plusieurs idées. Une idée c'est de peut-être déboucher sur des systèmes métalliques corrélés vrai-ment nouveaux et obtenir une température de transitionélevée … peut-être. Une autre c'est que beaucoup de cequ'on comprend du point de vue des phénomènes collec-tifs dans la nature ont été seulement compris à l'aide desystèmes de modèles magnétiques collectivement simplesalors que les systèmes frustrés maintenant ouvrent unevoie pour de la phénoménologie qui n'a pas été comprisejusqu'à ce jour. Une autre avenue qui est encore plus intel-lectuelle en fait c'est que ces systèmes fortement frustrés,une fois que la contrainte énergétique est imposée, peu-vent être décrits en terme de théorie de jauge et, que si tumets la mécanique quantique, tu te ramasses avec unethéorie de jauge quantique sur le réseau semblable à l'élec-trodynamique quantique. L'idée est donc d'explorer, peut-être de façon expérimentale, des phénomènes de décon-finement et de fractionalisation de charge qui ne sont paspossible facilement dans un cadre de physique des partic-ules. Trois papiers récents (deux dans Science et un dansNature) ont observé des excitations de type monopoles etdes “Dirac strings” dans les systèmes de “spin ice”…Parce qu'une fois que tu as un Hamiltonien effectif àlongue échelle, tu te moques de l'origine microscopique.


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Par exemple les excitations fondamentales à basse énergiedans la phase de verre de spin sont analogues au monopolede Dirac parce que quand tu brises la règle de la glace, tuflip un spin, tu peux représenter ça comme si t'avais créerune charge “plus”, une charge “moins” dans deux tétrahè-dres adjacents et ces deux charges plus et ces chargesmoins là interagissent par interaction Coulombienne où lacharge n'est pas le e2 mais c'est le moment magnétique μ2

et ces défauts là se propagent sur le réseau comme s'ilsétaient attachés par une, ce que l'on appelle une “Diracstring”. Il y a énormément d'intérêt présentement à savoirce que l'on peut attendre de ces genres de phénoménologiesur les monopoles.

BJ - L'autre aspect c'est que ces efforts expérimentauxau Japon, en Europe et au Canada dans ces systèmes frus-trés ont le potentiel de révéler des nouvelles classes decomportement électrique et magnétique ?

MG - Oui, des comportements collectifs qui donnentlieu à des genres de mélange en différents secteurs parexemple électrique et magnétique comme dans les multi-ferroélectriques ou peut-être si la frustration empêche dansle système métallique la phase magnétique de se dévelop-per peut-être que cela conduirait à la supraconductivité.Donc si l'échelle d'énergie est suffisamment haute onpourrait atteindre la température ambiante.

BJ - Entretemps c'est une aventure d'un problèmeintéressant à un autre problème intéressant.

MG - Oui.

BJ - Qu'est-ce qui te motives enfin ?

MG - En fait, je m'en fous un peu du sujet ... C'est unequestion de personnalité, si tu mets deux individus ensem-ble qui s'entendent bien, ils génèrent entre eux des motiva-tions, des questions qui peuvent mener à des collabora-tions. Donc finalement la raison pour laquelle je me suismis à travailler sur les systèmes frustrés c'est que quandj'ai rencontré Kiefl, on sait parler on s'est bien entendu, sicela avait été quelqu'un qui faisait du pliement de pro-téines, et j'avais été dans un laboratoire du NIH àWashington, j'aurais probablement travaillé sur lespliements de protéines.

BJ - Tu remplis le moule de beaucoup de théoriciensde la matière condensée. Ce sont des personnes qui aimentrésoudre des problèmes, c'est la passion intellectuelle ducasse-tête.

MG - Oui.

BJ - Tu as un problème, tu veux le comprendre.

MG - Oui, mais en plus par exemple il y a des individusqui ont vraiment un intérêt dans l'état solide, moi je m'enfous. Si on engageait un collègue au département qui fai-sait des expériences sur la physique biophysique, des pro-téines absorbées sur des polymères qui me propose unproblème qui m'intéresse, il y aurait a une possibilité decollaborer en principe. La question demeure alors celled'une cordialité mutuelle entre les individus pour dévelop-per une collaboration. -- Probablement que cela neprendrait pas beaucoup de temps pour que je me redirige,c'est simplement que cela ne s'est pas produit.

BJ - Tu as une liste de collaborateurs assez longue.

MG - Oui, l'autre truc qui était vraiment intéressant,c'est mon effort en “spin ice” c'est encore un truc qui estpersonnel, j'étais copain avec le type qui a découvert lespin ice avant qu'il ne découvre le “spin-ice”. Il était postdoc à ILL et quand ILL a fermé parce que le réacteur étaitbrisé il est allé passé six mois à TRIUMF travailler avecJess Brewer. On s'est rencontré puis on s'est mis à faire duski ensemble. C'est 5 ans plus tard quand j'étais àGrenoble, j'avais été invité à passer un weekend à faire duski et il venait juste de faire ses premières expériences surle spin ice., Puis il m'a raconté l'histoire, puis il je lui aidit “c'est bizarre que ça se produise comme ça dans tesmatériaux…” Donc tu vois ce n'est pas vraiment que j'aiété attiré seulement par la science pour travailler là-dessusc'est qu'en fait la possibilité de résoudre notre problème etde collaborer avec quelqu'un, et que la poursuite de lacompréhension du problème semblait possible immédiate-ment c'est cela qui m'a attiré.

BJ - Tu voyais la solution.

MG - Je ne voyais pas la solution. Je voyais la possibil-ité de collaborer avec quelqu'un sur un problème qui m'in-téressait. Donc ça prend trois parties, la partie expérimen-tale, la partie collaboration/dialogue et la partie mystère.

BJ - Il faut qu'il y ait un problème à résoudre, quelquechose à comprendre.

MG - Finalement pour tous les chercheurs la partiemystère est là. Les gens travaillent sur les problèmes dontils ne savent pas la réponse mais pour moi cela ne suffitpas. Il y a beaucoup de problèmes à résoudre. J'aimemieux travailler sur des problèmes qui peuvent donner lieuassez rapidement à une collaboration expérimentale.

BJ - Merci.


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2009 MEDALS AND AWARDS


Prof. Jeff Dahn

select group of scientists are great teachers andothers are great researchers. It is hard to findthis combination in one individual. Dr. JeffDahn is both, a leader in research and an inspir-

ing teacher. He was awarded the CAP Herzberg Medal in1996, for outstanding career achievement for a physicistless than 40 years of age. He is a Tier 1 Canada ResearchChair for Batteries and Fuel Cells, NSERC/3M IndustrialResearch Chair, recipient of an NSERCUniversity/Industry Synergy Award (2003), and is the 6thmost highly cited Materials Science researcher in theworld according to the ISI. What makes Jeff a deservingrecipient of theCAP TeachingMedal?

A good teachercommunicates dif-ficult concepts in aclear and under-standable way. Jeffuses “chalk andblackboard” andlecture demonstra-tions to conveyPhysics principles.He engages hisaudience andinvites furtherthinking. His lec-ture style balancesthe dual roles of instructor and entertainer, a skill thatensures his classroom is filled throughout the year. Whilethe methods are not new, in the hands of a skilled practi-tioner such as Jeff, they are a most effective teaching tool. An excellent and dedicated teacher sustains a high level ofperformance over his or her career. Jeff normally teachesfirst-year Physics classes with an enrolment of 300-400students. Over his 19 years of teaching Jeff has impacted

THE CAP MEDAL FOR EXCELLENCE IN TEACHING

LA MÉDAILLE DE L’ACP POUR L’EXCELLENCEEN ENSEIGNEMENT DE LA PHYSIQUE

the lives of approximately 6000 students – a small village!His teaching evaluations are (among) the highest in thefaculty, consistently scoring above 4.5 (out of 5) in thethree important categories of preparation, communicationability, and teaching effectiveness! As a result, Jeff hasbeen recognized with awards for excellence in teaching atboth Dalhousie and Simon Fraser.

A teacher inspires students and incites their intellectualcuriosity. Numerous teaching evaluation commentsdemonstrate that students not initially interested in Physicshave gone on in the field because of Jeff’s excellent teach-

ing methods. Jeffis enthusiastic,dynamic, well-spo-ken in a no-non-sense direct man-ner, and interjectshis lectures withinformal commentsthat are receivedwith amusement bythe students. A col-lection of theseappeared in hishonour on a studentw e b s i t e .Testimonials in hisfile reflect a fond-ness of the studentsfor him.

A teacher also inspires departmental colleagues. Jeff hasmentored several young faculty members in teaching firstyear Physics. His notes form the basis of 1st year lecturesand associated demonstrations (e.g. 72 demos in the fallsemester) taught by others. He drafts Computer AssistedPersonalized Assignments (CAPA) problems - which heestablished at both Simon Fraser in 1993 and at Dalhousiein 1997, participates in the undergraduate laboratories andgenerally inspires all of us to become better instructors.

Therefore, Jeff Dahn is a truly deserving recipient of theCAP Teaching Award for 2009.

Kevin HewittDalhousie University

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La Médaille de l’ACP pourl’excellence en enseignementde la physique est décernéeà Jeff Dahn, UniversitéDalhousie, pour son dévoue-ment exceptionnel à l’en-seignement de la physique auniveau supérieur du premiercycle, pour son pouvoir demotiver les étudiants àexplorer la physique en don-nant vie à ces concepts dansses cours, et pour son men-torat auprès des étudiants quise lançaient dans larecherche à tous les niveaux

The CAP Medal for Excellencein Teaching is awarded to JeffDahn, Dalhousie University,for his exceptional dedicationto superior undergraduatephysics teaching, his abilityto motivate students to studyphysics by bringing the con-cepts to life in his classes,and his mentorship of stu-dents engaging in research atall levels


RT – So, first of all, Jeff, congratulations on your welldeserved award. I think we would like to start by askingyou about your history on the teaching side. How andwhen did you get involved with the teaching?

JD – I joined Simon Fraser in 1990 and, like most start-ing professors, you are given the option to have reducedteaching in the first year or so and I said, NO, I want to seeif I like this or not. So, as soon as I got there I ended upteaching a small section of first year physics. It was elec-tricity and magnetism. It worked out well. I got to knowthe demos man at SFU, Jeff Rudd, and we started incorpo-rating a lot of demonstrations into that small class – wewere only about 50 people – so you had the advantage ofbeing able to inter-act with the stu-dents and then dodemonstrations,and it was reallyenjoyable. I didwell and I wasgiven one of the“in sequence” sec-tions, you know,that was 100 or so,and then I wasgiven the big first-year non-engineer-ing and physics life sciences track. It was about 350 stu-dents in one lecture hall at a time. That was fun. I did alot of demonstration-based teaching there. Around thattime it became clear to me that we didn’t have a methodfor getting the “one on one” interaction and learning expe-rience that the students needed in this large lecture format.

RT – This was sort of 1990?

JD – This was around 1993/94. This is when I becameaware of CAPA – Computer-Assisted PersonalizedAssignments for the first time. It was just under develop-ment at Michigan State and the guys there were making itavailable for people to try it. So we got it at Simon Fraserand I had a graduate student, Ian Courtney, code me up awhole bunch of problems that I designed for the engineer-ing track of physics. The whole idea was the problemswould not be calculator based where the numbers changedfrom homework to homework. They would be a lot ofconceptual things where diagrams change, graphs change,you ask questions about motion where graphs are in thereand there are ten different graphs that the computer selectsfrom. So typically a student and his/her friend wouldn’thave the same qualitative problem. What better way thanfor them to work together. They end up doing twice the

work because they understand each person’s problem.

So I really fell in love with this CAPA system and it is stillused at SFU and I took it with me to Dalhousie when Iwent there.

RT – Has CAPA evolved over the years?

JD – CAPA has evolved a lot. In fact, some textbookpeople like Halliday, Resnick [and Walker] will supplyCAPA problems with their book. So you get a wholelibrary of CAPA problems with their book. Every text-book supplier has some kind of an online physics / master-ing physics button, I think.

RT – So CAPAgrades?

JD – C A P Agrades and organizeseverything and keepstrack of the home-work. For us, CAPAand the resource cen-ter where the studentsgo to work together,or they can worktogether in the resi-

dence, whatever, that gives them that sort of ability toexplain to one another what is going on. I think that workspretty well.

RT – When you got into teaching, were there mentorsthat you had, or people from your past that you wanted toemulate in developing your teaching style?

JD – When I started at SFU I was kind of a little scaredabout “what am I going to be doing here?” So, I was luckyenough just to be able to sit in on a few classes that DarrylCrozier was giving and watched him do what he wasdoing and I thought -- that is not so bad, I should be ableto do that. In terms of people that I want to emulate – real-ly the people that made the biggest impact on me were --Ernie Guptill at Dalhousie taught me in first year physics.He was amazing. His demonstration-based lectures werereally incredible. So then Gerhard Stroink at Dalhousiewas involved with the Guptill class. He was the labinstructor and involved in a lot of the demonstrationsetups. I got to know him fairly well because he wasyoung and I really appreciated the work those guys wereputting into the demonstrations. Then when I movedalong, I think at Simon Fraser, Jeff Rudd, the demos manthere, was an enormous help and had incredible creativity


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"I am surprised, flat-tered, thrilled and some-what guilty (I have a50% teaching load) toreceive this award whichspeaks to the apparentsuccess of demonstra-tion-based lecturing tolarge classes."

« Je suis étonné, flatté,transporté et un peucoupable (j’enseigne àmi-temps) de recevoir ceprix qui témoigne du suc-cès manifeste des con-férences faisant appelaux démonstrationsdevant des classes nom-breuses. »

INTERVIEW WITH JEFF DAHN, JUNE 10, 2009, MONCTONNEW BRUNSWICK (BY R.I. THOMPSON)

july09-to-trigraphic-final.qxp 9/21/2009 5:09 PM 5

in terms of setting up demos that could work under theconditions of ten minutes to set up. At Simon Fraser thatwas all we had to deal with that. You know we wouldarrive at 6:00 a.m. and pack everything on our carts androll down to the lecture room and make sure we could setup in ten minutes and that everything was working andpack it all up, roll it back to the demos room and then,when it is time for class, roll back down, set up, and do itfor real. You really learned the importance of practice,practice, practice.

When I moved to Dalhousie I worked with Melvin Calkinat the beginning. We co-taught first year physics for awhile. He really was dead set against bringing a lot oftechnology into the lecture room. No powerpoint. Noway. It just goes too fast. Overheads. No way. It goestoo fast. Blackboard. Blackboard. Blackboard. So … Iagree with that too. That is what I have been doing.

And at Dalhousie Forest Fyfe has been a big player in thedemonstrations there. He is the demos man. Again,another guy with a lot of good ideas.

RT – For those readers who were not fortunate enough tohear your talk, can you summarize in a few sentences yourphilosophy to the sort of demo-based instruction?

JD – Yeah. You know you can do demonstrations just tobe flashy but that is really not the way I think you shoulddo it. You should set up with a demonstration in mind thatyou can quantify some aspect of it and then you make aprediction based on the physics you are trying to teach andthen that demonstration you measure the thing that youhave predicted and show that it matches. It is good if thedemonstration is a cool one as well. It captures their atten-tion and they remember what is going on.*

RT – Are you still developing new demos or do youlargely have the suite set for what you use in your cours-es?

JD – You would be surprised where demonstrationscome from. I think it is two years ago I was making upnew CAPA problems and that usually means you gather upevery textbook you can find and you go off in a corner andyou start flipping through the end-of-chapter problems andsay “hey, jeez, that is something I could adapt and make anice new CAPA problem out of”. Anyway, while I wasdoing that, I found a problem about walking the plankwhere you have a plank supported at one end and the otherend is a rope going to an overhead pulley. You hold theopposite end of the rope and you ask how far out onto theplank is it safe to walk. Doing the problem teaches youquite a lot about static equilibrium and it is just a naturaldemo -- large scale natural demo. So we built that one upand it worked really well. That’s the way it works. You

don’t know where an idea for a demo is going to comefrom.RT – Any place else that you … other than problemssets? Do you look at “Physics Teacher” or any of thesetypes of magazines?

JD – No.

RT – Web, or …

JD – I am a Canada Research Chair. I am an IndustrialChair of a research group of 37 people. I’m stretched farand wide. That is why I have been very fortunate to havecolleagues like Forest Fyfe, Jeff Rudd, and the other firstyear teachers at Dal – Ted Monchesky and Kimberly Hall– you know. Amongst all of us, whenever we see some-thing that is interesting we go for it. I don’t personallyread AAPT or the education-based journals. I just literal-ly don’t have time.

RT – Speaking of that direction, one of the things that Ialways talk about in terms of teaching, and I think manyof us do, is that classroom teaching is a small fraction ofthe teaching that we do. You just said you have a group of37, which I am guessing is everything from undergrads topostdocs. Can you talk a little bit about teaching in theresearch environment.

JD – I just won, in 2008, the outstanding graduate advi-sor award at Dalhousie – the first time it was ever given –so I must be doing something right. I think, when I start-ed as a professor, I had a very small research group and Iam a very driven person. I think I was in the face of mygraduate students too much so I was doing too much forthem. Now that the group is large, I just literally don’thave the time to do that so I am back at a distance, whichis probably the right distance so that they are able to takea look at their data and think about it before I am on top ofthem saying “okay, this is what it means and blah, blah,blah”. They have a chance to figure that out for them-selves. I sort of have developed a mode where I providethe resources that they need. I am there to talk to at anytime. I don’t have a computer in my office. I work in thelab on a workstation there so I am right in the middle ofthe whole thing at all times. I can see what is happening.People can bug me at any time. That means I am proba-bly not as productive as I could be in terms of doing thethings I am supposed to be doing, but it helps the students.Something is going right. There is no plan really.

RT – Using the words of the field, does your group basi-cally implement peer instruction? Is there a lot of interac-tion between more junior students and more senior stu-dents?

JD – Yeah. Our group is totally peer instruction. Whena new student comes in, it is kind of like “all right, are you


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* Ed. note: The front cover of this issue is from one of Jeff Dahn’s demonstrations. The Congress delegates who attended Jeff Dahn’s “2009 Excellencein Teaching Undergraduate Physics” medal talk were treated to a live demonstration (see page 141 for a description of how to make a light stick).


ready to make a lithium battery”, for example, “well, youare going to have to go learn that from Aaron Smith”, whojust learned it from somebody else. Students are alwaysteaching the other students. They teach each other how touse all of the major equipment, the x-ray diffractometers,the thermal calorimeters, you know, everything we have.I would say very peer instruction.

RT – You have a somewhat different background thanmany faculty in that you spent a number of years in indus-try between finishing grad school and becoming a facultymember. Does this impact in your teaching and does thebackground help you with interacting with either the stu-dents in your classes or the students in your group?

JD – I think it is a huge benefit on the research sidebecause we tend not to work too much on problems thatare sort of peripheral to the straight on, high importanceones. There are plenty of good problems to do that areimportant to society. That’s where we try to focus I guessand having that industrial background helps you under-stand what thing to work on maybe that has the potentialof being commercializable or not.

With respect to the first year class, I am not sure that ithelps so much. I have done things like spend the time todescribe how certain pieces of modern technology work inthe class; for example, [a] super capacitor. A few yearsago, I spent lectures on Lorne Whiteheads’ light pipe, forexample. It is a pretty neat thing to describe to them whenyou are doing reflection and refraction.

RT – In terms of your background and research side,some of the readers are not going to be familiar with thearea you work in. How about giving us the few-minute-version summary of what it is you do research on.

JD – I am a materials scientist and I decided to work onmaterials that are of importance for batteries and fuel cells,mainly in the area of energy storage and convergence.Our battery materials work has focused primarily on newelectrode materials for lithium-ion batteries and also onstudies of the processes that occur on the batteries underconditions of electrical and mechanical abuse that lead tosafety-related issues – fundamental studies of the safetyproblems of those cells. In the fuel cell side, we work onnew catalysts for fuel cells that can potentially lower thecosts and also improve the lifetime of the fuel cell. I havebeen doing materials work for almost thirty years, count-ing graduate school, and it is a situation where you makea material and then you test the material and see if it hasthe properties you want. In the last eight to nine years wehave adopted and brought into place a combinatorial sci-ence platform where we make, instead of one sample at atime, hundreds of samples at a time and then we screenthem in parallel for these different applications. We arereally the only research group actually in Canada so farthat has adopted this combinatorial method in materials

physics or chemistry.

RT – I am going to ask this in both directions but sincewe are talking about research we will start there. What arethe skill sets you look for your students to come out of ayear, or two-year, or six-year experience in your group,both in terms of technical skills and professional, orcareer, skills?

JD – You mean for my graduate students?

RT – Yes, for your graduate students.

JD – An exiting graduate student?

RT – Yes.

JD – This is a good question. You really want an exitinggraduate student to have an opportunity to have a situationwhere they have gone down a road that nobody has gonedown before, and they have had to tackle problems that Ican’t say “Andrew, this is what it means and this is whatyou need to do”. He has got to say “Okay Jeff, this is whatI think it means and this is what I want to do to solve theproblem”. I am using this guy Andrew Todd as an exam-ple. He is a student that is just finishing now and weencountered a research problem where we decided weabsolutely had to do some small angle x-ray and neutronscattering on the materials to figure out what was goingon, and I had really no experience in either of these tech-niques so Andrew said “okay this is what we are going todo. We’ll do a directed studies course. I’ll teach you andme about small angle x-ray and neutron scattering. I’llapply for beam time at the neutron facility at NIST inMaryland and then we’ll do these experiments”. That iswhat happened. He just took it on and did it. By the timea student can do that, well they are ready! That’s what astudent has to be able to do … figure out what needs to bedone, learn how to do it, and do it and move on. That’s atypical kind of scenario.

RT – So then, backing off, do you have a set of goals inmind for your undergraduate course where you are teach-ing 300 students. Ideally, what would you like those stu-dents to come out of your course with that they did nothave coming in?

JD That is a good question. That is one of the thingsyou learn when you come to conferences like this and gointo the physics education sections … a lot of people saythat you should have a list of outcomes that you want thestudents to have at the end of the course. I don’t reallyhave anything in mind, per se, going in other than ‘okay,we are going to cover this set of material and we are goingto hope that the students learn it to the point that they canremember it down the road’. I had an example not longago where two guys came to see me – I can’t even remem-ber who they were – and they said “you know, in yourclass, when you dropped that magnet down the copperpipe and it went really slow – that was five years ago but


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we still remember that and we are in civil engineering andwe have a problem where we have to drop somethingdown to the bottom of a well and it can’t go fast. We wantit to go slow. It’s in a steel pipe and we are wondering ifwe can use a rare earth magnet to make this thing go niceand slowly down to the bottom”. That’s the kind of thingthat you want to hope something sticks. That is what I amhopeful of … something sticks.

RT – Another one of the favourite buzzwords of thephysics education community is ‘blended learning’. Ican’t even give you a perfect definition of it. Your lectur-ing style is very much demonstration-based and demon-stration leading to ideas and concepts. I assume thiscourse has a lab or tutorial?

JD – Yes, it has a lab.

RT – Is there any integration between the lectures andthe labs and the topics covered with your demos?

JD – Yes, the lab and lecture follow along in sequence.Typically we will be covering material in the lecture aweek before or simultaneously with what is going on inthe lab. I demonstrate in one of the lab sections onMonday afternoon and that is really fun because I get then

to meet about 20% of the class or so, which I would nevermeet on the floor of a class that size. You can really thensee what they know and what they don’t know. You areamazed at the beginning when they come into the firstsemester, out of high school, and they have some data thatthey need to plot and try to plot on a piece of paper. Someof them take forever to figure out what scale range tomake the graph on to how the data. You think the simplestthings like plotting your graph are maybe a waste of time– they should immediately go do it on the computer – butyou learn, well maybe it is not such a waste of time afterall. The lab is supposed to integrate with the lectures andthe CAPA is supposed to provide the one-on-one kind ofproblem solving and back and forth interaction with theirpeers. Using CAPA, of course, is advantageous becausethey are not working on the same problem. It really dis-courages copying.

RT – I think that covers the questions I had. Any mes-sage for physics instructors out there to sort of wrap thingsup?

JD – I would say that, if you are having fun doing whatyou are doing, you are going to do a better job than if youare not having fun doing what you are doing. If you arenot having fun doing what you are doing, do something


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Prof. Guy Moore

rofessor Guy Moore currently works in one of themost fascinating fields of contemporary science,the one preoccupied with the understanding of thebulk, collective behaviour of Quantum

ChromoDynamics (QCD), the theory of the strong interac-tion. Guy seeks to answer questions like: What happens ifone compresses and heats atomic nuclei to extreme limits?What goes on deep inside a dense neutron star? Couldphase transitions inthe early universehave cosmologicalimplications? Whatdoes one observe iflarge, massivenuclei are collidedwith each other atvelocities very nearthat of light? Hiswork aims to deep-en our understand-ing of the verynature of the theo-ry, while providing testable predictions and interpretationsthat can be investigated experimentally. Such ambitiousgoals demand a special individual: simply put, Guy Mooreis a theorist with impressive versatility. He combines deepphysical insight and intuition with sophisticated mathe-matical rigor and advanced numerical techniques.

Moore’s main work in recent years has featured relativis-tic many-body field theory, and has produced seminalbreakthroughs. Some of these are now milestones on theroad that leads to the understanding of the quark-gluonplasma, a new phase of matter predicted by QCD andinvestigated experimentally at facilities around the world.Guy’s work has indeed been extremely relevant for thevigorous experimental heavy-ion collision program beingconducted at the Relativistic Heavy Ion Collider (RHIC)at the Brookhaven National laboratory, and for the near-future experimental program at the Large Hadron Collider(LHC) at CERN, in Geneva. These experiments createdroplets of super-high temperature matter, composed ofthe building blocks of neutrons and protons, the quarksand gluons. Such a plasma also existed during the firstmicroseconds following the Big Bang. Professor Moore’swork characterizes the behaviour of this novel matter,focusing on its dynamics. His work on the hydrodynamicproperties, particularly the viscosity of this fluid, are con-sidered the state of the art in the field and have beeninstrumental in demonstrating that the quark-gluon plasma

is a strongly-coupled system. Recently he has extendedthis investigation to bulk viscosity and higher order trans-port coefficients. He has also investigated a limitation inthe usual thinking about such plasmas; their instability torunaway magnetic field growth, as in conventional plas-mas. Moore has demonstrated that this magnetic fieldgrowth is more limited in quark-gluon plasmas than in thesort of plasmas investigated for fusion energy; but that

such instabilitiesmay still have animportant role indetermining howthe quark-gluonplasma behaves.

Guy Moore hasalso done importantwork on studyingthe behaviour ofsome relatively rareconstituents of thequark-gluon plas-

ma that have particularly clean experimental signatures.He has investigated the way the plasma should interactwith heavy quarks such as charm and bottom quarks. Hehas computed the rate at which the plasma emits photons(how brightly it shines); after 7 years his work on thisproblem remains the state of the art. He has also developedformalism for studying the energy loss of highly energeticquarks or gluons which are proving a key experimentalobservable. With collaborators at McGill, he has appliedthis formalism to observations at RHIC and provided arather accurate description both of energy loss for high-energy quarks and gluons, and of photon production.

Professor Moore’s earlier work used similar many-bodytheory tools to study the very early Universe, focusing onthe problem of understanding the origin of the Universe’snet abundance of matter over antimatter. This may have

P

La Médaille Herzberg estdécernée à Guy Moore,Université McGill, pour le pro-fond impact de ses contribu-tions à la physique théoriquedes particules, tel le com-portement collectif de massede la chromodynamiquequantique dans des condi-tions extrêmes de tempéra-ture et de densité.

The CAP Herzberg Medal isawarded to Guy Moore, McGillUniversity, for the broadimpact of his contributions totheoretical particle physics,such as the bulk and collec-tive behaviour of quantumchromodynamics underextreme conditions of temper-ature and density.

THE CAP HERZBERG MEDAL(FOR OUTSTANDING ACHIEVEMENT BY A PHYSICIST AGED 40 OR LESS)

LA MÉDAILLE HERZBERG DE L’ACP(POUR CONTRIBUTIONS EXCEPTIONNELLES PAR UN PHYSICIEN DE 40 ANS OU MOINS)



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occurred at a phase transition called the electroweak phasetransition, when the universe was about 10?11 secondsold, the last time when the net abundance of matter overanti-matter could change. Guy Moore did pioneering workin understanding the dynamics of this phase transition. Healso addressed the question of how efficiently mattercould be created in this transition, a property known as the“sphaleron rate.” His work on this problem resolved thequestion of the efficiency of matter creation and is one ofthe key building blocks to the (still incomplete) under-standing of how matter may have come into being.

Moore has also worked on several projects outside this“main line” of research. His work on atomic Bose conden-sation clarified how the Bose condensation temperature ofa cold atomic gas is modified by interactions between thegas atoms. His work with his student Joshua Elliottshowed how to study certain supersymmetric field theo-

ries using the tools of lattice gauge theory. In cosmology,he has shown that “phantom” field explanations for thedark energy, which violate the weak energy condition,generically violate observational bounds on cosmicgamma rays. And he has used the observation of extreme-ly high energy cosmic rays to place extremely tight con-straints on any violation of Lorentz symmetry breaking,both within particle physics and gravity.

Guy’s intellectual leadership in a large variety of differentresearch areas is an inspiration: One does not have to sac-rifice theoretical depth to scientific eclecticism. TheHerzberg Medal has found a worthy recipient.

Charles Gale, ChairMcGill University

GM – I was born in Colorado.

BJ – Colorado: Mountains, ski,…

GM – Yes, it’s very far from any oceans or actual gen-uine rivers. We had little things that we thought wererivers at the time, but now we live next to the St-LawrenceRiver, I have to consider them little trickles. If you cancross it without getting wet above the knee, it’s not reallya river.

BJ – OK, so youwere really up inthe mountains?

GM – No, no,everyone inColorado lives onthe plains right infront of the moun-tains. Like 5%who live deep onthe plains, maybe10% live in themountains andeveryone else livesright on the frontrange. It’s too bigof a pain to buildhouses in the mountains. It’s much easier on flat land. Buteveryone wants to spend their time in the mountains sincethey all live in front of the mountains, like Boulder. That’swhat Boulder is, when you come down the mountains and

as soon as it’s flat, that’s what Boulder is.

BJ – You studied in Boulder?

GM – I didn’t study in Boulder. I grew up North ofBoulder, halfway between Denver and the Wyoming bor-der, just south of Fort Collins.

BJ – Is that considered far west, cowboy country?

GM – Well Iknew quite a fewpeople in highschool that worecowboy hats, butthey were a socialsub-class.

BJ – It’s like inBC – there are somecowboy hat and thencity type people

GM – Yes, butyou know in a smalltown, you have amix of them. Therewere a couple ofHewlett Packard

plants that my father worked in before being transferred toFort Collins. He didn’t feel like moving his family, so hetravelled back and forth. It’s not that far. That was thebeginning of the sort of knowledge industry in Colorado.

"I am thrilled and sur-prised to receive theCAP Herzberg medal.The medal means a lotto me; as a foreignnational it makes mefeel fully accepted bythe Canadian physicscommunity, and as aphysicist it is wonderfulto see such recognitionfor my work."

« Je suis transporté etétonné de recevoir laMédaille Herzberg del’ACP. Cette médaille apour moi une grande sig-nification; en qualité deressortissant étranger,cela m’amène à me sentirpleinement accepté parla collectivité canadiennede la physique et, enqualité de physicien, unetelle reconnaissance demes travaux est mer-veilleuse. »

INTERVIEW WITH GUY MOORE, JUNE 10, 2009,MONCTON NEW BRUNSWICK (BY B. JOÓS)


How do you get knowledge kind of people to agree towork somewhere, you choose somewhere that they’llenjoy living.

BJ – The ocean or the climate or mountains …

GM – Historically, the people lived right on the frontrange. The most productive way to practice agriculture isto grab the runoff of the snowmelts, it’s quite dry, like thedry parts of Saskatchewan and so the first time the riverscome down the mountains, is the right time to seed. Thereis far less water available than from the land. All the irri-gation farming is done by the mountains. So, historically,there are a lot of little farming communities which justmushroomed into these modern American stripmall citytypes.

BJ – Right, the modern economy doesn’t care where itis actually.

GM – For the majority of jobs. Some jobs have to be incertain places. Most of them are mobile.

BJ – How did you get into physics?

GM – My father is an engineer. He had, I think, wantedto be a physicist, he had his most interest in physics, buthe didn’t have the patience to be in school such a longtime. He went into electrical engineering and apparentlywas quite successful. I don’t know if he pushed me intothis direction or not, maybe he didn’t, because 4 out of the5 of us, didn’t go into physics.

BJ – So, the reason you went into physics?

GM – I think it’s like everything else, I found it fascinat-ing and I had a very good 8th grade science teacher. Ilearned a lot of chemistry and a certain amount of physics.There were a couple of good teachers in high school, notactually in physics, but in other sciences. And I had thefeeling I was behind in physics because I was having thesegood chemistry classes and hadn’t had a physics class.One summer, I checked out one of these physics booksand tried it out and it seemed like fun. I was one of thosepeople who was half way in between being like a mathperson and being like a science person. And what I endedup doing by some series of accidents, I got ahead in mymathematics and ended up taking the Advance PlacementCalculus exam. In the 11th grade, there was no more mathto do in the high school, so in my last year in high school,I started sneaking off to the university to take my mathclasses and while I was there, I decided to take freshmanphysics. So I never took high school physics.

BJ – What university was that?

GM – Colorado State University. I was driving 3 days aweek to Fort Collins to take classes. It would have been

more efficient to go to university at the age of 17. Then Iwent to Harvey Mudd College in Clairmont California formy undergraduate. I majored in physics. In one respect itwasn’t a good idea but in most respect, it was very posi-tive. There was no graduate program there, it was under-graduate only. And so, I reached a point where I ran out ofcourses to take.

BJ – So you moved onto the next step.

GM – So then I went to grad school and when I arrivedat Princeton I discovered that I was probably a term or ayear behind.

BJ – You didn’t have the high power courses.

GM – I think I was sort of the middle of my class there,I was not even in the normal class at Princeton. JuanMaldacena was in my class. He is one of the SeniorFellows at the Institute for Advanced Studies. He is of thatgeneration of string theorists, he is considered top. EvaSilverstein considered one of the top theorists and ChetanNayak who is a big wheel in quantum computing now,were all in my class. So I was sort of in the middle of thepack.

BJ – So they carried you.

GM – It was a very good experience. I think it was thebest experience for me. I’m somebody who obsessivelywants to know about things further, wider away than whatthey necessarily need to know about, which I think is atendency of physicists. So, one of the advantages for meof Harvey Mudd College was that I have an extraordinar-ily big breadth of knowledge. I had to take three terms ofchemistry and I had to take a system engineering course,and I had to take 12 semesters of humanities. Princetonalso had a big requirement in general physics. We had todo an experiment which was sort of the edge of what Icould manage. I think I did ok but, being competent atdoing an experiment is not what decides whether youshould be an experimentalist. Enjoying the challenge offiguring out things, really liking messing with all of thecabling and instrumentation, that has to set your pulsegoing and it just didn’t. So I knew I should not be anexperimentalist.

BJ – There is always this background that most peopleshould be experimentalists and very few people should betheorists

GM – I basically think this is true. Here I am sitting asa theorist saying that. I must not have messed around withenough electronics as a kid.

BJ – What was the climate at Princeton?

GM – The climate, at that time in particle physics?Everyone was shifting to string theory and I went to a few


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string theory lectures and I just wasn’t convinced that thatwas the right direction to take.

BJ – Have you read the book “The Trouble withPhysics” by Lee Smollin? His basic message is that thereare too many people doing string theory.

GM – Yeah, but I don’t like Lee Smollin either. I don’treally agree with Lee because I am not too sure that he’sany better than they are.

BJ – So you didn’t do string theory.

GM – So I looked around for the people who were notdoing string theory.

One of them was Neil Turok.

BJ – He was at Cambridge (Editor’s note, currently theDirector of the Perimeter Institute)

GM – At that time he was at Princeton. He moved toCambridge, a year and a half before I finished. He tookme as a student in 1994 and he moved to Cambridge in 96.

BJ – So he stayed long enough to get you going.

GM – At that time he had about 7 students which ismore than you could really handle and so he didn’t fundme at Princeton. At that time you were completely fund-ed by your TA. The first few years I was on a NSF schol-arship for 3 years so it was just the last 2 years that I wasTAing. The main thing Neil Turok was working on at thattime was electroweak-bariogenesis. Specifically, this isthe issue that in cosmology we observed that for every1 billion microwave photon there is one proton or neutronand no antimatter. So why is there matter and no antimat-ter?

BJ – That’s the big question.

GM – So that is the big question that everyone is tryingto address here. Sakharov told us in the 60s, before I wasborn, that any explanation either has to say that it wasthere from the beginning or that both baryon number isviolated and CP is violated, and there is a departure fromequilibrium from right when moment baryon number isessentially violated to when it is being conserved. Andthen at the beginning of the 80s it was first consideredlikely and subsequently basically reinforced this belief,mostly, that there was an epoch of inflation early in the bigbang. And it’s very hard to see how there could be a net abaryon number after inflation because it dilutes every-thing. It does not matter if there were baryons before infla-tion, they would be now spread apart so much that therewould be essentially none. So these are the three myster-ies: why is there 70% dark energy, 21% dark matter, andthirdly the 4% that we are made off, where did it come

from? Baryon number is violated at the temperature corre-sponding to the Higgs mass, according to the standardmodel…(Ed. Elaborates on issue and his contributions)The consensus within the minimum standard model is thatwe are never out of equilibrium with the Higgs mass esti-mates and we never have an opportunity to have thebaryons made.

BJ – So you mean this is not the way to go?

GM – If they discover that the boring old standardmodel Higgs is correct, this is not the way to go. If theydiscover something more interesting then that extraphysics of whatever is more interesting can make thisreappear even if the Higgs is heavy…

BJ – With the current model, you don’t have the solu-tion?

GM – There are lots of current models …

BJ – You moved on to other things

GM – I moved on to other things. This involved devel-oping a lot of understanding in the technology of many-bodied physics and particle physics, finite temperaturefield theory, really worrying about dynamics, real timebehaviour not just the thermodynamics. And so we havesome nice tools for understanding those things and thereare still some interesting questions to look at and sort of ona whim, as sort of a good example of a well posed welldefined question that people didn’t understand, let’s see ifwe can understand viscosities in these theories. So weended up doing these far more complicated then we everexpected studies of the viscocity of non-abelian gauge the-ories. But there is very complicated physics involved. Thestickiest part for us was that some of the constituents in aplasma are rather high energy. The Maxwell distributionhas this tail but the tail turns out to have a lot to do withviscosity. Some of the particles are the hardest to get themto go in different directions. They have a large role in car-rying and diffusing momentum. An important thing is thatthey radiate Bremsstrahlung. They scatter all the time. …

BJ – Where were you then?

GM – This started in my second postdoc and it endedwhen I was already at McGill. We basically figured outhow to deal with this toward the end of my second post-doc.

(Ed. Returning to the Princeton days)

GM – At Princeton while I was working on these bario-genesis issues, Neil took me as a student and immediatelysort of threw an idea for a project because he had sevenstudents, he was busy, he had three postdocs, he was doingthis and doing that, and I worked with one of his postdocs


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and then he went off to Cambridge and I was left on myown and then I did some projects and the first thing I didwas try to understand this efficiency of bariogenesis andreally got some things to work that Neil always wanted towork on. He was still my advisor but I had had little con-tact with him for a year and a half. After he had leftPrinceton, I spent a summer in Cambridge where weworked together and wrote two papers together. I think Imore often collaborated with people not at my institution.It started already in grad school. Since I was Neil’s stu-dent, I was also part of the gravity group. You know aboutthe gravity group?

BJ – No, I don’t know

GM – Jim Peebles, Wilkinson, Joe Taylor, all the juniorfaculty in astrophysics, all the students and postdocs andso forth. We’d meet together once a week, in Princeton,there would be two half hour talks, and everyone wasexpected to give a talk every year or sometimes twice ayear, and if you didn’t volunteer you’d be dragooned. Itcould be a review talk, it could be what I’m doing orresearch talks,

BJ – An interesting paper?

GM – Yes, for instance, one time I gave a talk, I thoughtthat I would summarize what’s up nowadays with the bigbang nucleosynthesis, one time I gave a talk I thought Ishould explain exactly why the baryon number should beviolated in the standard model.

BJ – Which was your thesis.

GM – It was close, yes, and there was one guy who likedgiving talks where he said what’s NASA up to. They werejust sending something to Mars and you had to learneverything about the space probe. It was a very diversegroup. They were all working on things related to astro-physics and cosmology and it got to expose all to thesedifferent things. One of the things we have to do as physi-cists, is to keep exposed the things around are own field. Ifind it difficult to keep up with what they’re doing inatomic physics but at least I like to know what the neutri-no guys are up to and what the supernova guys are up to.I think you should know a little about the things that arearound your field. That was a great opportunity to do that.As an example, as to how strong a group they were at thattime, Vicki Kaspi was in that group, she overlapped withme there, Barth Netterfield was in that group. That was 3people that won the CAP Herzberg all in the same group,in the last five year or so.

BJ – Vicki is Canadian right?

GM – Vicki is from Montreal, an undergrad at McGill,she married the son of a physics professor at McGill whois long retired, she left her job at MIT to go to McGill

because her husband got a job at the hospital. Otherwise,she would probably be tenured at MIT. The otherCanadian in that group at the same time who is a very suc-cessful junior professor was Doug Stairs’ daughter IngridStairs. She got tenure already at UBC. Somehow she gother faculty position faster than I did. All these talentedpeople are doing better than me. That’s part of life atPrinceton. So, one of the guys presenting here, for exam-ple, Mike Romalis, he started a year after me at Princeton,graduated at the same time as me, despite being an exper-imentalist, who always take at least six years to finish, andwhen I arrived as a postdoc at the University ofWashington he was a postdoc who they were just hiring asa faculty member, they needed him that badly.

BJ – Good experimentalists are rare, sometimes theyget them even before they’ve done a number of postdocs.It’s a gamble.

GM – And before I finished my postdoc there, he’d beenhired away by Princeton, where he is now tenured.

BJ – So you follow these very successful people.

GM – Yeah, it’s important to feel bad.

BJ – It is motivating?

GM – Something like that. Yes, it was a very successfulgroup at that time. And then I took a postdoc at McGill,and I worked with Jim Cline, that was sort of the end ofthe electroweak-bariogenis days.

BJ – You were a postdoc at McGill?

GM – Yeah, my first postdoc was at McGill and then mysecond postdoc was at the University of Washington inSeattle. And then I was hired as a faculty at McGill.

I was hired right after Rob Myers left, not that I actuallythink I’m a replacement for Rob Myers. So when I went toMcGill, and all of this effort in understanding how correct-ly to calculate these processes. And it turns out that thereis loads of in heavy ion collisions that could be used todescribe what you need to know about the energy losswhen there are these occasional high energy particles inthe plasma.

BJ – What you talked about yesterday?

GM – Yes, I had to skip these details because I had 25minutes and I thought, for some reason, it was moreimportant to understand how on earth you can tell when abunch of things fly out from a point, how they interactwith each other, that’s what I was trying mostly to convey.I think a lot of understanding talk giving and teachingwhich are almost the same thing, is knowing what to con-centrate on and what to skimp on. What are the take home


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ideas and what are the things that are distractions. Theaudience completely changes the way you present things.BJ – So what do you teach at McGill?

GM – Well, for several years, I taught a Physics of musiccourse. That was an interesting challenge, because I thinkone third of the students were musicians, one third werescientists and one third were neither.

BJ – Art students or …

GM – People who thought it sounded like an interestingtopic. And so, anything that you wanted to explain therewas usually some way of explaining it using a lot of sci-entific concept of thinking and there was some way ofexplaining intuitively to the musicians that might be verydifferent, then you had to explain it in two or three differ-ent way. Actually, it’s a good technique anyway, if youhave time, you should always explain to everyone 2 or 3times.

BJ – That’s what education experts say.

GM – It’s true. It helped me understand things person-ally, to find two completely different ways of thinkingabout them.

BJ – But everything boils down to waves, so you haveto give a course on waves.

GM – The one disadvantage, is that you can’t see thewaves, but you hear them.

BJ – You can hear them through a demonstration.

GM – You can do all of them. I did on average twodemonstrations per lecture. I’ve played tones at them andasked them what they thought of these tones. Is their hear-ing uniformly spaced in frequency, then you play 500 Hz,1500 Hz, 2500 Hz and then you realize it like (makingpitch sounds …). And then after a while they’re almost allthe same and you so no, it’s totally not evenly spaced.What about evenly spaced in period and the same thing astotally not that either, what about log spaces and that oneis. You all agree that those were evenly spaced, and theysay yeah, so you all agree that you have to learn about logsand then they see that logs automatically naturally arise.

BJ – You like teaching.

GM – Yes, I enjoyed that class particularly, I also taughtthe graduate quantum field theory course.

BJ – Obviously that was your bag.


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GM – it was not an easy course to each

BJ – It’s very technical

GM – It’s technical and you have to really work …

BJ – There’s no shortcut…

GM – There’s no shortcut. It’s a challenge becausethere’s a lot of new mathematical technique, there’s a lotof new technical stuff and there’s a lot of really not obvi-ous concepts. We have to assign homework that they haveto spend 15 hours a week doing homework. Because if wedon’t, they won’t learn and this is another thing aboutteaching is that if you don’t make them do homework,they don’t learn anything. They think they know, theythink they understood, but you only understand when youuse it. Understanding means being able to use it. And ifthe material is really hard, then you’ll have to assign a lotof homework and then you have to structure the home-work that even though it’s hard, they’ll able to do it.

BJ – What drives you?

GM – I think most physicists are driven by curiosity.

BJ – They have different styles. You seem to have builtyour own independent approach.

GM – Yeah, I had to be more independent starting as agrad student, particularly after my advisor left. I dealtwith that fairly well. Then I had to learn how not to workby myself in order to collaborate with others, That took meprobably a postdoc and a half.

BJ – There’s another challenge in that field is thatyou’re trying to reproduce a certain reality.

GM – But my early work was much more on thingswhere they’re were few numbers and then the big theoryand then you’re trying to fill in all the blanks. What I’vebeen working on more recently has a lot more data to it.But on the flip side, I work with sort of phenomenologicalpeople who are very data driven, and I’m sort of the more“in principle” theorist member of the collaboration.Collaboration is for multiple people because they have dif-ferent expertise. A lot of the collaboration is working onvery practical problems and I’m on the sort of theory endof the collaboration and somebody else in on the interfacewith data end of the collaboration , In ten years maybe Iwould be up to the wrist instead of up to the knuckle.

BJ – Thank you.

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Prof. RichardPeltier

rofessor Peltier ranks among the world’s top andmost highly-cited Earth Scientists, and his workhas touched deeply upon a wide range of the mostoutstanding problems in the discipline. His early

pioneering work on the mathematical theory of the glacialisostatic adjustment, along with his extensions of thiswork over the past decade, revolutionized this field ofstudy, making pos-sible the develop-ment of a detailedunderstanding ofthe interactionsbetween the solidEarth, continentalice-sheets on itssurface and theoceans that haveoccurred duringepisodes of plane-tary glaciation.This work hasanswered questionsranging from varia-tions in mantle viscosity to the extent to which moderntide gauge measurements of global sea level rise due toglobal warming are contaminated by glacial isostaticadjustment.

Professor Peltier has also made major contributions in theareas of mantle convection, fluid dynamics of the atmos-phere and oceans, and the global climate variability of theLate Quaternary period. Of particular note in the contextof the CAP award are the following:

• Beginning from the earliest stages of his career,Professor Peltier has maintained an interest in, andmade seminal contributions to, the understanding of theimpact of the series of pressure induced phase transi-tions that occur with increasing depth in the outer iron-magnesium-silicate shell that bounds the molten ironouter core of the planet from above. This work led tothe discovery of the so-called “avalanche effect”. Hismodels of this process have enabled thermal historiesof the planet to be constructed that satisfy the Ureyratio constraint upon the volume concentration of heatproducing radioactive elements that the interior of theplanet should contain. This problem with previousmodels of the thermal history of the Earth had remainedoutstanding for several decades.

• Peltier’s visco-elastic field theory of the process ofglobal glacial isostatic adjustment connects very close-ly to this work on the mantle convection process as itprovides the means whereby it has been possible forhim to infer the effective viscosity of the mantle and itsvariation with depth. This transport coefficient is a crit-ical ingredient required for the construction of models

of the convectionprocess that under-lies continentaldrift. This body ofwork now serves asthe basis for allmodern investiga-tions in this area.Its accuracy hasmost recently beenstrikingly con-firmed by the pre-dictions that havebeen made using itof the time depend-ence of the gravity

field of the planet that is currently being measured bythe GRACE (Gravity Recovery and ClimateExperiment) satellite system.

• A most subtle physical process also recently explainedfor the first time with this theory concerns the impact ofthe variations in the planet’s rotational state that havebeen forced by growth and decay of vast continentalscale ice sheets over the past million years of Earth his-tory. He has very clearly established that the “wander”of the pole of rotation relative to the underlying geog-raphy of the planet impresses a pattern of spherical har-monic degree 2 and order 1 structure onto the variationsof global sea level that occur in response to ice-ageoscillations in continental ice cover. This pattern hasonly recently been unambiguously detected in a global

PLa Médaille de l’ACP pourcontributions exceptionnellesà la physique est décernée àRichard Peltier, Université deToronto, pour ses apportsféconds à la compréhensionde la physique de la Terre,dont l’ajustement isostatiqueglaciaire, la convection dumanteau, la dynamique desfluides de l’atmosphère et desocéans et la variabilité du cli-mat planétaire.

The CAP Medal forAchievement in Physics isawarded to Richard Peltier,University of Toronto, for hisseminal contributions tounderstanding the physics ofthe earth, including glacialisostatic adjustment, mantleconvection, fluid dynamics ofthe atmosphere and oceans,and global climate variability.

THE CAP MEDAL FOR ACHIEVEMENT IN PHYSICS

LA MÉDAILLE DE L’ACP POUR CONTRIBUTIONSEXCEPTIONNELLES À LA PHYSIQUE



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data base of radio-carbon dated relative sea level histo-ries that has been compiled in his Toronto laboratory.

Most recently, Professor Peltier has been named the inau-gural Director of the Centre for Global Change Science atthe University of Toronto, and been named ScientificDirector of SciNet, a newly established University ofToronto facility for large scale scientific computationrecently funded through CFI, the Province of Ontario andthe University of Toronto with a budget of ~$50M over 5years. He has also served as a Lead Author on one of theChapters of the recently published Fourth AssessmentReport (AR4) of the Intergovernmental Panel on ClimateChange (IPCC). His achievements have led to numerousawards and honours, including Fellowships in the

American Geophysical Union, the AmericanMeteorological Society, the Royal Society of Canada andthe Norwegian Academy of Science and Letters, as well asSloan, Steacie, Killam and Guggenheim Fellowships. Heis the recipient of the Bancroft Award and RomanowskiMedal of the Royal Society of Canada, the Paterson medalof the Meteorological Society of Canada, the J. TuzoWilson Medal of the Canadian Geophysical Union, theMilankovic Medal of the European Geosciences Unionand the Vetleson Prize of the G. Unger VetlesenFoundation of New York.

Michael LukeUniversity of Toronto

I was delighted to be informed of this award by the CAPPresident, especially so as I expect that the sub-field of thediscipline in which I work, planetary physics, is an areathat is not as often represented in leading physics depart-ments as it once was. For this reason, among many, I con-sider myself very fortunate to be spending my career in thePhysics Department of the University of Toronto.Although dissentingviews do exist, mycolleagues and I gen-erally share the viewthat the diversity ofthe discipline is agreat source of itsstrength. In thisregard I was veryinterested over thepast year, as a mem-ber of the committeestruck by theResearch Councils ofthe UK to review thestate of our disciplinein the UnitedKingdom, that this issue achieved some prominence in ourdiscussions. In the formal Report (visithttp://www.rcuk.ac.uk/news/081001.htm to download acopy), the importance of diversity as a buttress against thefragilty that often attends hyper-specialization (in scienceas in ecology) was an important consideration in ourassessment of the health of the physics enterprise.

If I were to place the work that I do within the currents ofdiscovery that are presently enlivening the field, I wouldsee it as concerned generally with the physics of a partic-ular complex system, the Earth primarily, but also involv-ing its sister planets in our solar system. I was very fortu-nate, even as an undergraduate at the University of BritishColumbia, to have come into contact through the coursesI took, with scientists whose interests were in the geophys-

ical sciences. I decided to do graduate work in Torontoafter hearing Tuzo Wilson speak at a seminar on plate tec-tonics in the mid-1960’s when this revolutionary idea wasstill in its formative stages. Although my own doctoralthesis was written on the development of ideas in theoret-ical hydrodynamics for application to the plate tectonicsphenomenon, it was finally supervised by C.O. Hines,

whose name is stillsynonymous withthe physics of theEarth’s upperatmosphere. WithColin I was able tos imul taneous lydevelop a rudi-mentary under-standing of themechanics ofh y d r o d y n a m i cwaves and of theatmosphere andoceans in general.My subsequentcareer has been

one in which I was equipped at the outset to work as com-fortably on the physics of planetary interiors as on thephysics of atmospheres and oceans. I therefore see myselfas having benefited enormously from the fact that I waseducated in a physics milieu in which diversity was bothrespected and actively nurtured.

My current work has come to be ever the more stronglyfocused upon the problem of global climate change. Myinitial objective in this work has been to test the modelswe employ to make predictions of the future warming tobe expected as a consequence of atmospheric greenhousegas increase by subjecting them to the test enabled by theclimate states that are inferred to have been characteristicof times in the (sometimes distant) past. Generally speak-ing the state-of-the-art models employed to make such

RESPONSE BY RICHARD PELTIER

"I'm both delighted andhonored to be namedthe 2009 recipient of theCAP Medal forAchievement in Physics.I consider the award toequally acknowledge theefforts of the talentedstudents and post doc-toral fellows with whomI have been fortunate towork."

« Je suis à la foisenchanté et honoré d'êtreen 2009 le récipiendairede la médaille de l'ACPpour contributionsexceptionnelles à laphysique. J'estime quece prix souligne égale-ment les efforts des étu-diants et chercheurspostdoctoraux talentueuxavec qui j'ai eu la chancede travailler. »


predictions pass the tests posed by such paleo-climatolog-ical inferences, although there are extremely interestingissues that continue to drive further advances in under-standing. This milieu has of course come to be intenselypoliticized, perhaps especially in Canada where it hasbecome a source of regional friction, primarily betweenthe hydrocarbon rich provinces of the west, and the ROC.It is a sad fact that the governments of such provinces aswell as the current national government have sought coverfor our rapidly rising greenhouse gas emissions in the illinformed rhetoric of our local community of “climate

deniers”. Although the reality of greenhouse warming andits cause in anthropogenic emissions has been acceptedrather universally since publication of the most recent(2007) report of the Intergovernmental Panel on ClimateChange, “rumps” of scientific illiteracy persist in ourcountry and continue to be exploited for political advan-tage. In my opinion such a “disconnect” between scientif-ic truth and the political response to it is enabled by apolitical structure within which science has no formalplace.


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2009 CANADA-WIDE SCIENCE FAIR

The 49th Annual Canada-Wide Science Fair, held in May 2009 in Winnipeg, Manitoba, was once again a resounding suc-cess! Over $150,000 in cash, scholarships and other prizes were won by the participating students. This year, the CAPsponsored an award for the best physics project in the senior category. The prize consisted of a cash award of $1,000 plusa CAP plaque commemorating their achievement. The winner of the 2009 CAP prize was:

It’s Time to Make a “Radon” the Basements

This project was an experiment to determine the most effective and efficient sys-tem used to remove radon from basements. A model home was built and testedusing carbon dioxide gas to gather comparative results. Building a sub-slab filledwith gravel and using a fan to create a negative air pressure within the sub-slab wasthe most effective system.

About the winner:

At the time of the award, Tegan Wiebe was a grade 12 student at W.C. EaketSecondary School in Ontario. She hopes to attend McGill University this year tobecome an architect and, eventually, work abroad. Her passions are vast and

numerous. She enjoys mountain biking,tennis, basketball, photography, andplaying the piano. In the past two yearsshe has competed at the OFSAA levelfor tennis and the NOSSA level for longjump in track and field. She was also aleader for the community youth groupand she volunteered in a program thattalks to grade 7’s and 8’s about peer pres-sure.

THE 2010 CWSF WILL BE HELD IN PETERBOROUGH, ON FROM MAY 15-23, 2010

Tegan WiebeGrade 12W.C. Eaket Secondary SchoolBlind River, ON


cap medal for outstanding achievement in … filel aurÉats et p rix de 2009 la physique au canada /...

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