arXiv:cond-mat/9710343 · Physical review. B, Condensed matter

Confined coherence and analytic properties of Green’s functions

Kurt Schönhammer

Published Aug 15, 1998• 7 citations

Abstract

A simple model of noninteracting electrons with a separable one-body potential is used to discuss the possible pole structure of single-particle Green's functions for fermions on unphysical sheets in the complex frequency plane as a function of the system parameters. The poles in the exact Green's function can cross the imaginary axis, in contrast to recent claims that such a behavior is unphysical. As the Green's function of the model has the same functional form as an approximate Green's function for coupled Luttinger liquids, no definite conclusions concerning the concept of ``confined coherence'' can be drawn from the locations of the poles of this Green's function.

DOI: 10.1103/physrevb.58.3494

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