scienze matematiche, fisiche, naturali università di pavia facoltà di dipartimento di fisica “a....

ScienzeScienze Matematiche, Fisiche, NaturaliMatematiche, Fisiche, Naturali Università di Pavia

Facoltà di

Dipartimento di Fisica “A. Volta”

In 1799 Alessandro Volta invented the battery. He was then 54 years old and one of Europe’s most famous physicists. Since 1778 he had been Regius Professor of Experimental Physics at the Pavia University and been running the Physics Laboratory, which has been recently reconstructed.

Not only is our Department named after him... but also the unit of measure of potential, which Volta called "tension", is named the "volt".

http://ppp.unipv.it


Facoltà di


MAGNETISM and SUPERCONDUCTIVITY GroupStaff: A. Rigamonti, F. Borsa, P. Carretta, M. Corti, A. Lascialfari, S. Aldrovandi, L. Spanu, E. Micotti, N. Papinutto, M. Filibian, M. Mariani

•Motions and structure of flux lines lattice in superconductors•Low-dimensional quantum antiferromagnets (S=1/2)•Molecular nanomagnets•Quantum tunneling of the magnetization (QTM)

RAMAN, LUMINESCENCE, Hall SPECTROSCOPIES Group + EPR & MAGNETIZATION GroupStaff: G. Samoggia, P. Galinetto, E. Giulotto, F. Rossella + C.B. Azzoni, M.C. Mozzati

•Phase transitions in pure and mixed oxides based on ABO3 (KTO, STO, BTO, etc) compounds•Structural, electronic and optical properties of intrinsic and impurities defects in ABO3 related materials (e.g. LiNbO3)•Study of the transport phenomena and charge localization due to optical irradiation in ABO3 compounds


Facoltà di


PHYSICS EDUCATION and PHYSICS HISTORY GroupStaff: G. Bonera, L. Borghi, A. De Ambrosis, L. Falomo, L. Mascheretti, M.C. Garbarino, L. Cardinali

*Identification of tools and strategies to support the Physics teaching/learning process*Historical comprehension of the developments of different physical branches, taking into account not only the technical aspects but also the global cultural and social context.

QUANTUM INFORMATION THEORY GroupStaff: GM D’Ariano, C. Macchiavello, M. Sacchi, P. Lo Presti, F. Buscemi, G. Chiribella, P. Perinotti

•Quantum Measuring Devices for Photonics and Quantum Information •Entanglement Assisted High Precision Measurements •Quantum Teleportation and Quantum Cloning by the optical parametric squeezing process •Quantum Properties of Distributed Systems


Facoltà di

Photonic Materials and Nanostructures


http://fisicavolta.unipv.it/dipartimento/ricerca/fotonici

Pavia, July 5th, 2005

European School of Advanced Studies

9th Master course in Materials for micro and nano-technologies

and

http://chifis.unipv.it/euro/

Staff: A. Stella, G. Guizzetti, F. Marabelli, L.C. Andreani, M. Patrini, M. Galli + post-Docs & PhD students


Facoltà di

Our Research Labs

Optical Spectroscopy Lab

Laboratory of Nonlinear Optics and Ultrafast Spectroscopy (M. Malvezzi. Dip. Elettronica)

CILSOMAF Centro Interdipartimentale Laser,

Spettroscopia Ottica e Materiali per FotonicaCollaboration Dip. Fisica, Chimica Fisica, Chimica Generale, Elettronica Location: Area Cravino (clean room, chemistry labs, laser lab, optical spectroscopy lab, SEM lab) ... under construction


Facoltà di

Our main Research activities

1. Growth and fabrication of nanostructured surfaces and interfaces

2. Investigation of the optical properties and optical Characterization at high resolution and sensitivity

3. Design and Modelling of materials structures and their optical properties ( then feedback to 1)

NoE PHOREMOSTNano Photonics to REalize MOlecular

Scale Technologies

www.phoremost.org


Facoltà di

Why micro and nano-structures?

3D - Bulk 2D – QWell 1D - QWire 0D - QDot


Facoltà di

Nanostructured surfaces and interfaces

Vollmer - Weber mode (nanoparticles)

Stranski - Krastanov mode (quantum dots)

Molecular Beam Epitaxy & Atomic Layer MBE

Opal sedimentation

Bottom-up...

Chemical Etching of waveguides

Lithography + Post-growth treatments

...or top-down?

Si

SiO2

Polystyrene opals


Facoltà di

NPs :Vollmer - Weber mode

A BAB

Young Equation:

Growing layer wants to minimize interface energy and its own surface energy Layer “balls up” on the surface

Nucleation of heterogeneous systems : liquid A on a solid B

TEM image of Ga NPs in SiO2

Average radius from 2 to 50 nmSize dispersion 20%

= 0 < /2

=

A

BAB = A cos - B

D (nm)


Facoltà di

QDs: Stranski-Krastanov mode

~ 2 ML of InAs on GaAs

Strain induced growth of pyramidal QDs

STM image


Facoltà di

III-V devices: MBE & ALMBE

Artificial sArtificial strutruccturetures withs with sub- sub-micromicrometric periodicitymetric periodicity, , with with optical properties designed optical properties designed and tunable as a function of and tunable as a function of the sample parameters (lattice the sample parameters (lattice constant, strain, quantum constant, strain, quantum effects).effects).

Aim: Obtain particular device Aim: Obtain particular device performancesperformances

HRTEM of InGaAs/InP Multi Quantum Wells


Facoltà di

Why optical spectroscopies?

Linear processes

+ Nonlinear ones


Facoltà di

Linear optics for characterization

Optics and spectroscopy (0.1 – 500 m)

Reflectometry, ATR , -reflectometry

Ellipsometry

Raman and luminescence

Laser light scattering

Nonlinear optical response (time res)

Optical functions

Surface and interface properties: roughness, planarity, composition, porosity, long-range order, oxides, overlayers

Thicknesses up to 1 ML and NP dimensions

Alloy compositions, dopants and impurities (< 1013 cm-3)

Structural disorder


Facoltà di

Nonlinear Optics

Spectra Physics system composed by a pump laser Millennia, Ti:sapphire oscillators Tsunami emitting 70/130 fs and 1-15 ps

pulses @ 780-820 nm,

fs Optical Parametric Oscillator tunable from 1400 to 1800 nm

Regenerative amplifier and OPA

SHG & THG,

Hyper Rayleigh scatteing

Pump & probe techs


Facoltà di

Silicon: what is it?

Poly Si thin film

The intensity and the position of the E1 and E2 interband critical points depend on grain size and crystallinity

SpectroscopicEllipsometry


Facoltà di

Photonic crystals & waveguides

The analog of electronic structures for light, allowing to control light

propagation and emission in 1, 2 or 3 dimensions

dispersion of photonic bandsPHOTONIC BAND GAP slowing down /superluminal propagation of light pulses zero-threshold laser?

0.0

0.5

1.0

= 2

= 2

= 2

= 1

= 1

= 1

= 1

TE, odd

X

Ene

rgy

(eV

)


Facoltà di

Design and control the lattice strain effects for tuning the emission wavelength to 1.31 /

1.55 m (optoelectronics)

InAs/InGaAs QDots


Facoltà di

SHG amplification by metal NP glasses

R = 20 nm

Tnl (

10-2

2 cm

2 /W)

Temperature (K)

Amplification by surface plasmon resonance@ solid-liquid phase transitions

25

50

75

100

300

400

500

600

0

0.02

0.04

0.06

25

50

75

100

300

400

500

600

2550

75100

0

1

2

R

R (nm)

(nm)

Tnl(a.u.) Hyper-

Rayleigh Scattering by metal nanoparticle solutions

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