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Using crossed electric and magnetic fields to manipulate collisions of molecules Roman Krems University of British Columbia

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Page 1: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Using crossed electric and magnetic fields to manipulate collisions of molecules

Roman Krems University of British Columbia

Page 2: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields
Page 3: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

UBC group:

Zhiying Li Erik Abrahamsson Timur Tscherbul

Collaborations:

Alexei Buchachenko - Moscow Grzegorz Chalasinski - Warsaw Alex Dalgarno - Harvard John Doyle - Harvard Gerrit Groenenboom - Nijmegen Sture Nordholm - Sweden Maria Szczesniak - Michigan

Page 4: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 5: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 6: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 7: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 8: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 9: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 10: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 11: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 12: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 13: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 14: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 15: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 16: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 17: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 18: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 19: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 20: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 21: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 23: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 24: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 25: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 26: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 27: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 28: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Principles of external �eld control of molecular dynamics

• Close or open channels by the Zeeman/Stark e�ect

• Break the spherical symmetry of the problem

• Mitigate the role of centrifugal barriers in the reaction

• Induce Feshbach resonances that enhance reactivity

• Suppress or enhance the role of spin-orbit interactions

• Induce anisotropic interactions

Page 31: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 33: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 34: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 35: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 36: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 37: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 38: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 39: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 40: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 41: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 42: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 43: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 44: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 45: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 46: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Controlling Collisions of Ultracold Atoms with dc Electric Fields

R. V. Krems*Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada

(Received 14 August 2005; revised manuscript received 12 March 2006; published 28 March 2006)

It is demonstrated that elastic collisions of ultracold atoms forming a heteronuclear collision complexcan be manipulated by laboratory practicable dc electric fields. The mechanism of electric field control isbased on the interaction of the instantaneous dipole moment of the collision pair with external electricfields. It is shown that this interaction is dramatically enhanced in the presence of a p-wave shape orFeshbach scattering resonance near the collision threshold, which leads to novel electric-field-inducedFeshbach resonances.

DOI: 10.1103/PhysRevLett.96.123202 PACS numbers: 34.50.!s, 34.20.Gj

The creation of ultracold atoms and molecules has led tomany ground-breaking discoveries described in recent re-view articles [1]. Particularly interesting is the possibilityto control interactions of ultracold atoms and moleculeswith external electric and magnetic fields [2]. External fieldcontrol of atomic and molecular dynamics may lead tonovel spectroscopy methods, provide detailed informationon mechanisms of chemical reactions, and allow for thedevelopment of a scalable quantum computer [3]. Externalfields may be used to tune the scattering length for mo-lecular interactions and alleviate the evaporative cooling ofmolecules to ultracold temperatures [4]. Collisions of ul-tracold atoms can be controlled by magnetic fields usingFeshbach resonances [5] or by lasers [6,7]. Here, we showthat ultracold collisions of atoms forming a heteronuclearcollision complex can also be controlled by dc electricfields due to the interaction of the instantaneous dipole mo-ment of the collision pair with external fields. The interac-tion is dramatically enhanced in the presence of a p-wavescattering resonance near collision threshold, which allowsfor the possibility to tune the scattering length of ultracoldatoms by laboratory available electric fields. This providesa new mechanism to control elastic scattering, inelasticenergy transfer and chemical reactions in collisions ofatoms and molecules at zero absolute temperature.

Electric field control of atomic and molecular interac-tions may offer several advantages over magnetic fieldcontrol and optical methods. The evaporative cooling ofatoms and molecules is most easily achieved in a magnetictrap, where magnetic field control of collisions may becomplicated due to varying magnetic fields of the trap.Electric fields induce anisotropic interactions. The studyand control of anisotropic collision properties at ultracoldtemperatures may uncover new phenomena in condensedmatter physics—hence the recent interest in polar Bose-Einstein condensates [8]. Anisotropic interactions mayalso be used to connect qubits in a quantum computer[3], and schemes for electric field control of atomic andmolecular interactions are particularly relevant for quan-tum computation. Electric field control may be applicableto systems without magnetic moments or systems, for

which s-wave Feshbach resonances cannot be induced ina practicable interval of magnetic fields. Finally, electricfield control of atomic collisions may provide a sensitiveprobe of scattering resonances corresponding to nonzeropartial waves so the mechanism described here can be usedfor high-precision measurements of molecular states nearthe dissociation threshold.

Marinescu and You [9] proposed to control interactionsin ultracold atomic gases by polarizing atoms with strongelectric fields. The polarization changes the long-rangeform of the atom-atom interaction potential and modifiesthe scattering length. The interaction between an atom andan electric field is, however, extremely weak, and fields ofas much as 250 to 700 kV=cm were required to alter theelastic scattering cross section of ultracold atoms in thecalculation of Marinescu and You. The maximum dc elec-tric field currently available in the laboratory is about200 kV=cm [10]. We propose an alternative mechanismfor electric field control of ultracold atom interactions anddemonstrate that the scattering length of ultracold atomscan be manipulated by electric fields below 100 kV=cm.

We consider collisions in binary mixtures of ultracoldgases. Mixtures of ultracold alkali metal atoms have beencreated by several experimental groups [11,12]. When twodifferent atoms collide, they form a heteronuclear colli-sion complex which has an instantaneous dipole momentso it can interact with an external electric field. The inter-action is weak. The dipole moment function of the colli-sion complex is typically peaked around the equilib-rium distance of the diatomic molecule in the vibration-ally ground state and quickly decreases as the atoms sepa-rate. Only a small part of the scattering wave functionsamples the interatomic distances, where the dipole mo-ment function is significant. At the same time, the inter-action with an electric field couples states of differentorbital angular momenta. The zero angular momentums-wave motion of ultracold atoms is coupled to an ex-cited p-wave scattering state, in which the colliding atomsrotate about each other with the angular momentum l "1 a:u: The probability density of the p-wave scatteringwave function at small interatomic separations is very

PRL 96, 123202 (2006) P H Y S I C A L R E V I E W L E T T E R S week ending31 MARCH 2006

0031-9007=06=96(12)=123202(4)$23.00 123202-1 2006 The American Physical Society

d

E

Page 47: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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(K)

The energy of Li and Cs in the states

with mfLi = 1 and m

fCs

= 1

Page 48: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 49: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 51: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 52: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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Page 53: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

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n (Å

2 )PRL 96, 123202 (2006)

Page 54: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Controlling spin relaxation of molecules with electric fields

1/2j =

N = 1

0N =

j = 3/2

j = 1/2

Page 55: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

0 25 50 75 100 125 150

Electric field (kV/cm)

3×10-6

4×10-6

5×10-6

6×10-6

7×10-6

8×10-6

Cro

ss s

ectio

n, Å

2

CaH

Page 56: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

0 25 50 75 100 125 150

Electric field (kV/cm)

10-5

10-4

Cro

ss s

ectio

n, Å

2

CaH

CaD

Page 57: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

0 25 50 75 100 125 150

Electric field (kV/cm)

10-5

10-4

10-3

10-2

10-1

Cro

ss s

ectio

n, Å

2

CaH

CaD

Molecule with rot constant 1 K

Page 58: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

0

2

4

Ene

rgy,

cm

-1

0 20 40 60Electric field (kV/cm)

4

4.5

5

5.5

∆E

, cm

-1

CaD; B = 0.1 T

Page 59: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

0

2

4

Ener

gy, cm

-1

0 20 40 60

Electric field (kV/cm)

4

4.5

5

5.5

!E

, cm

-1

CaD; B = 0.1 T

1/2j =

N = 1

0N =

j = 3/2

j = 1/2

Page 60: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

0 20 40 60

Electric field, kV/cm

2

2.1

2.2

2.3E

nerg

y, c

m-1

CaD; B = 4.7 T

Page 61: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

4.4 4.6 4.8 5

Magnetic field, T

10-2

100

102

Cro

ss s

ectio

n, Å

2

0 20 40 60 80

Electric field, kV/cm

10-2

100

102

Cro

ss s

ectio

n, Å

2

E = 20 kV/cmE = 20 kV/cm

Spin relaxationin CaD - He collisions

Zero electric field

Page 62: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

� ������� ������"����� � ������� )", �������� !"��#%$&�('()�*+'���*�*�,

� � ����� � � ��� � ��� � ������� ������ �

� q � ��� ��� � q�p � ��� � � q�p � � q

triplet state

singlet state

A + BCB + AC

� ��������

Page 63: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Rigorous scattering calculations with �elds are very di�cult

Page 64: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Rigorous scattering calculations with �elds are very di�cult

No external fields

15 calculations with less than

yesyesyes 128 coupled states each

Page 65: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Rigorous scattering calculations with �elds are very di�cult

No external fields

15 calculations with less than

yesyesyes 128 coupled states each

In a magnetic field

31 calculations with up to

yesyesyes 808 coupled states each

Page 66: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Rigorous scattering calculations with �elds are very di�cult

No external fields

15 calculations with less than

yesyesyes 128 coupled states each

Parallel electric and magnetic fields

B E

31 calculations with up to

yesyesyes 808 coupled states each

Page 67: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Rigorous scattering calculations with �elds are very di�cult

No external fields

15 calculations with less than

yesyesyes 128 coupled states each

Parallel electric and magnetic fields

B E

31 calculations with up to

yesyesyes 808 coupled states each

Nonparallel electric and magnetic fields

BE

1 calculation with

yes 10,368 coupled di�erential equations

Page 68: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

0 20 40 60 80

Angle between the fields, degrees0

50

100

150

200

250C

ross

sec

tion,

Ų

B = 4.7 T

Zeeman relaxation in CaD - He collisions

E = 20 kV/cm

Page 69: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Conclusions

Page 70: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Conclusions

70 80 90 100 110

Electric Field (kV/cm)

102

104

106

108

Cro

ss s

ectio

n (Å

2 )

PRL 96, 123202 (2006)

• Electric-�eld-induced resonances• May also occur in molecule - molecule collisionsy (The dipole moment of RbCs - RbCs is 6 Debye)

Page 71: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Conclusions

70 80 90 100 110

Electric Field (kV/cm)

102

104

106

108

Cro

ss s

ectio

n (Å

2 )

PRL 96, 123202 (2006)

• Electric-�eld-induced resonances• May also occur in molecule - molecule collisionsy (The dipole moment of RbCs - RbCs is 6 Debye)

Page 72: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Conclusions

70 80 90 100 110

Electric Field (kV/cm)

102

104

106

108

Cro

ss s

ectio

n (Å

2 )

PRL 96, 123202 (2006)

• Electric-�eld-induced resonances• May also occur in molecule - molecule collisionsy (The dipole moment of RbCs - RbCs is 6 Debye)

Page 73: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Conclusions

70 80 90 100 110

Electric Field (kV/cm)

102

104

106

108

Cro

ss s

ectio

n (Å

2 )

PRL 96, 123202 (2006)

• Electric-�eld-induced resonances• May also occur in molecule - molecule collisionsy (The dipole moment of RbCs - RbCs is 6 Debye)

Page 74: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Conclusions

70 80 90 100 110

Electric Field (kV/cm)

102

104

106

108

Cro

ss s

ectio

n (Å

2 )

PRL 96, 123202 (2006)

• Electric-�eld-induced resonances• May also occur in molecule - molecule collisionsy (The dipole moment of RbCs - RbCs is 6 Debye)

0 25 50 75 100 125 150

Electric field (kV/cm)

10-5

10-4

10-3

10-2

10-1

Cro

ss s

ectio

n, Å

2

CaH

CaD

Molecule with rot constant 1 K

Page 75: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Conclusions

70 80 90 100 110

Electric Field (kV/cm)

102

104

106

108

Cro

ss s

ectio

n (Å

2 )

PRL 96, 123202 (2006)

• Electric-�eld-induced resonances• May also occur in molecule - molecule collisionsy (The dipole moment of RbCs - RbCs is 6 Debye)

0 25 50 75 100 125 150

Electric field (kV/cm)

10-5

10-4

10-3

10-2

10-1

Cro

ss s

ectio

n, Å

2

CaH

CaD

Molecule with rot constant 1 K

4.4 4.6 4.8 5 5.2Magnetic field, T

10-2

100

102

Cro

ss s

ectio

n, Å

2

Zero electric fieldE = 20 kV/cmE = 40 kV/cm

0 20 40 60 80

Electric field, kV/cm

10-2

100

102

Cro

ss s

ectio

n, Å

2

20 kV/cm 40 kV/cm

Zero electric field

Page 76: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Conclusions

70 80 90 100 110

Electric Field (kV/cm)

102

104

106

108

Cro

ss s

ectio

n (Å

2 )

PRL 96, 123202 (2006)

• Electric-�eld-induced resonances• May also occur in molecule - molecule collisionsy (The dipole moment of RbCs - RbCs is 6 Debye)

0 25 50 75 100 125 150

Electric field (kV/cm)

10-5

10-4

10-3

10-2

10-1

Cro

ss s

ectio

n, Å

2

CaH

CaD

Molecule with rot constant 1 K

4.4 4.6 4.8 5 5.2Magnetic field, T

10-2

100

102

Cro

ss s

ectio

n, Å

2

Zero electric fieldE = 20 kV/cmE = 40 kV/cm

0 20 40 60 80

Electric field, kV/cm

10-2

100

102

Cro

ss s

ectio

n, Å

2

20 kV/cm 40 kV/cm

Zero electric field

0 20 40 60 80

Angle between the fields, degrees0

50

100

150

200

250

Cro

ss s

ectio

n, Å

²

B = 4.7 T

Zeeman relaxation in CaD - He collisions

E = 20 kV/cm

Review papers:

some-space Eur. Phys. J. D 31, 149 (2004).

some-space Int. Rev. Phys. Chem. 24, 99 (2005).

Page 77: Roman Krems University of British Columbiagroups.chem.ubc.ca/krems/talks/TalkTellurideJun06.pdf · 2015. 12. 24. · Contr olling Collisions of Ultracold Atoms with dc Electric Fields

Quantum Chemistry and Ultracold Physics

• Interactions between atoms and molecules at long range

some-space Interaction Anisotropy

some-space Spectroscopic accuracy

some-space Heavy (Metallic) Systems

• E�ects of �elds on molecular structure

• Dipole moment functions for complexes of atoms and molecules

• Non-adiabatic e�ects

Review papers:

some-space Eur. Phys. J. D 31, 149 (2004).

some-space Int. Rev. Phys. Chem. 24, 99 (2005).