[kolokvij-ijs] prof. dr. Antonio Bianconi, Univerza v Rimu "La Sapienza" - sreda, 1.2.06

[Eva Tozon]

Kolokvij na IJS

PROF. DR. ANTONIO BIANCONI
Oddelek za fiziko
Univerza v Rimu "La Sapienza"
Italija

FESHBACHOVA RESONANCA IN PARJENJE ELEKTRONOV V PLASTOVITIH SISTEMIH
(Feshbach shape resonances and interband pairing in layered materials)

We discuss the Feshbach shape resonances in superconducting superlattices of
quantum wires and quantum wells, providing the mechanism for evading
temperature decoherence effects. The talk will cover the historical
development of the idea of Fano - Feshbach resonances will be presented
starting from the Auger effect to the atomic autoionization lines to the
shape resonances for neutron capture in nuclear phsyics up to the recent use
of Feshabch resonances to rise the critical temperature of quantum
condensates in ultracold gasses.
A Feshbach shape resonance in the interband proximity effects is shown to
occur in multiband superconductors in the clean limit where the disparity
and negligible overlap between electron wave-functions in different subbands
suppresses the single electron interband impurity scattering rate.  The Fano
Feshbach shape resonances in  multicomponent superconductors is
characterized by quantum superposition of pairs in states corresponding to
different spatial locations; it occurs by tuning the chemical  potential
near a Van Hove-Lifshitz singularity (vHs) in the electronic energy spectrum
of the superlattice associated with the change of the Fermi surface
dimensionality of  one of the subbands.

Predavanje bo v angleščini. Vabljeni!

V SREDO, 1. FEBRUARJA 2006, OB 13. URI
Velika predavalnica Instituta "Jožef Stefan"
Institut "Jožef Stefan", Jamova 39, 1000 Ljubljana, http://www.ijs.si