Thursday 24 June 2004 at 15:00
Jindřich Kolorenč
(Department of Condensed Matter Theory, Institute of Physics ASCR, Prague)
Towards mean-field theory of Anderson metal-insulator
transition - part II:
Parquet scheme and the asymptotic limit to high
spatial dimensions
Abstract:
In this seminar, a model of noninteracting disordered electrons is
studied in high spatial dimensions in order to develop a mean-field
description of Anderson localization transition. Off-diagonal
one- and two-particle propagators are found to behave as Gaussian
random variables with respect to momentum summations. With this
simplification the parquet equations for two-particle irreducible
vertices are reduced to an algebraic equation for a single local
quantity. The time-reversal invariance, displayed as the electron-hole
symmetry of two-particle functions, plays a substantial role in such a
reduction as well. We find a disorder-driven bifurcation point in the
resulting equation that signals vanishing of diffusion and onset of
Anderson localization.
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