Beginning of new series of seminars.

[Cond.Matt. & Stat.Mech.Section]

JOURNAL CLUB SEMINAR

on

Disorder and strong electron correlations



Friday, 6 November   -    11:00 a.m.



Seminar Room,  Leonardo Building - first floor





Markus MÜLLER ( I.C.T.P. )



"Purely electronic transport in strongly disordered, but nearly  
superconducting insulators"

Abstract



Certain strongly disordered superconducting films, when driven  
insulating by reducing thickness or by a small perpendicular magnetic  
field, are believed to maintain a strong pairing of electrons into  
localized Cooper pairs, the phase transition to an insulator merely  
signaling the loss of phase coherence across the sample.  The ensuing  
bosonic insulator has a variety of very peculiar properties:  
empirically, it is found to exhibit a simply activated resistance of  
purely electronic nature.

I will analyze the new question of the spectral properties of the  
disordered interacting system across the phase transition in the light  
of the phenomenon of localization in Fock space. This analysis leads  
to a possible explanation of the above-mentioned properties in terms  
of localized Cooper pairs which couple only very weakly to phonons.  
Open and controversial issues will be discussed.



REFERENCES:

M. Müller, arXiv:0909.2260

I.L. Aleiner, B.L. Altshuler, G.V. Shlyapnikov, arXiv:0910.4534