CM seminar coming up

[CM ICTP - Trieste]

CONDENSED MATTER SECTION

	
SEMINAR on   Disorder and strong electron correlations



Thursday, 15 February   -    11:00 a.m.



Lecture Room 'C',  Main Bldg.- terrace level




V.E. KRAVTSOV   ( The Abdus Salam I.C.T.P. )


"Cooper instability near the Anderson transition"


Abstract

	We consider the simplest model of a disordered superconductor in which 
electron interaction is attractive near the Fermi surface and the 
Coulomb repulsion is absent.  In contrast to classical BCS theory we 
assume the multifractal statistics of near critical one-particle 
eigenstates near the Anderson transition.  Using different 
approximations for the temperature of Cooper instability and generating 
the multifractal states from the corresponding random-matrix ensembles 
we find this temperature to be drastically increased at the Anderson 
transition and behaving like a power 1/(1-D_2/3)~1.6 of the 
dimensionless attraction constant.  Here D_2 is the correlation fractal 
dimension of the single-particle eigenfunction which for the 3D 
Anderson model is approximately equal to 1.3.  We also study the 
superconducting temperature as a function of the 
localization-correlation length in the vicinity of the Anderson 
transition and show that the superconductivity persists in the Anderson 
insulator until the level spacing in the localization volume becomes of 
the order of the critical temperature exactly at the transition.