Level statistics inside the core of a superconductive vortex
Abstract
Microscopic theory of the type of Efetov's supermatrix sigma-model is constructed for the low-lying electron states in a mixed superconductive-normal system with disorder. The developed technique is used for the study of the localized states in the core of a vortex in a moderately clean superconductor (1/\Delta << \tau << 1/\omega_0 = E_F/\Delta^2). At sufficiently low energies E << \omega_{Th}, the energy level statistics is described by the "zero-dimensional" limit of this supermatrix theory, with the effective "Thouless energy" \omega_{Th} \sim (\omega_0/\tau)^{1/2}. Within this energy range the result for the density of states is equivalent to that obtained within Altland-Zirnbauer random matrix model of class C. Nonzero modes of the sigma-model increase the mean interlevel distance \omega_0 by the relative amount of the order of [2\ln(1/\omega_0\tau)]^{-1}.
Cite
@article{arxiv.cond-mat/9805296,
title = {Level statistics inside the core of a superconductive vortex},
author = {M. A. Skvortsov and V. E. Kravtsov and M. V. Feigel'man},
journal= {arXiv preprint arXiv:cond-mat/9805296},
year = {2009}
}
Comments
5 pages, RevTeX. One error is corrected, also two references are added. Submitted to JETP Letters