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Journal of Physics C Solid State Physics

On a new systematic approach to the problem of disordered systems

Martin V. K. Úlehla

Published Mar 10, 1980• 0 citations
Publisher

Abstract

In this work the authors show how a model disordered problem can be simply reformulated and the averaged Green functions calculated in an orderly and systematic fashion by methods of quantum field theory. For convenience and definiteness, the authors consider a theory described by a random binary (tight binding) Hamiltonian with a diagonal and off-diagonal disorder.

DOI
10.1088/0022-3719/13/7/009

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In this work the authors show how a model disordered problem can be simply reformulated and the averaged Green functions calculated in an orderly and systematic fashion by methods of quantum field theory. For convenience and definiteness, the authors consider a theory described by a random binary (tight binding) Hamiltonian with a diagonal and off-diagonal disorder.
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The disorder averaged single-particle Green's function of electrons subject to a time-dependent random potential with long-range spatial correlations is calculated by means of bosonization in arbitrary dimensions. For static disorder our method is equivalent with conventional perturbation theory based on the lowest order Born approximation. For dynamic disorder, however, we obtain a new non-perturbative expression for the average Green's function. Bosonization also provides a solid microscopic basis for the description of the quantum dynamics of an interacting many-body system via an effective stochastic model with Gaussian probability distribution.