CM Seminar

[ICTP info point]

CONDENSED MATTER AND STATISTICAL PHYSICS SECTION
	
INFORMAL SEMINAR on   Disorder and strong electron correlations



Thursday, 2 March    -    11:00 a.m.


Room 239,  Main Bldg.- II floor



M. FABRIZIO    ( SISSA, Trieste )


"Kondo physics and strongly correlated superconductivity in model 
fullerene conductors"


	Abstract

The effects of electronic correlations on superconductivity are 
investigated by means of Dynamical Mean Field Theory (DMFT) in a model 
for alkali doped fullerenes.  It is shown that the proximity to a Mott 
transition amplifies the s-wave phonon-mediated pairing mechanism built 
into the model.  It leads to a superconduting pocket adjacent the Mott 
insulator with a large superconducting gap in comparison with the 
corresponding BCS value.  The physical properties of this strongly 
correlated superconductor are compatible with the experimental data 
available on fullerenes.  Yet, contradicting the common belief for 
fullerenes,  superconductivity in the model is not of the BCS-type nor 
is the normal state a conventional Fermi-liquid.  We find on the 
contrary several aspects which rather resemble those of cuprate 
superconductors, such as an increase of Drude weight accompaning the 
onset of superconductivity.  We identify the origin of these anomalies 
to the unconventional properties displayed by the Anderson impurity 
model for a C60n- molecule onto which the lattice model maps within 
DMFT.