For distribution

[CM ICTP - Trieste]

SEMINAR on  Disorder and strong electron correlations




Thursday, 4 October   -    11:00 a.m.



Seminar Room,  Main Bldg.- first floor



A. SILVA   ( The Abdus Salam I.C.T.P. )


"Adiabatic quantum pumping in interacting systems"


Abstract

	Adiabatic quantum pumping in noninteracting, phase coherent systems is 
elegantly described by Brouwer's formula.  The latter expresses 
geometrically the charge pumped per cycle in terms of the scattering 
matrices.  Interactions within the dot, while suppressing phase 
coherence, make Brouwer's formalism inapplicable.  In the presence of 
interactions, is a geometric description of pumping still possible?  
And what are the new, important physical processes brought in by the 
presence of interaction?  In this talk, I will discuss recent work 
focusing on giving an answer to these questions.  In particular, I will 
discuss the interaction corrections to Brouwer's formula and show that 
they are related to inelastic scattering events.  As an illustrative 
example to discuss the role of inelasticity in pumping I will consider 
the effect of interaction with a bosonic bath on a resonant level 
quantum pump.  Finally, as a second example of interacting quantum 
pump, I will describe the exact solution of the problem of pumping in 
quantum dots in the Kondo regime (at the Toulouse point).