Home
For authors
Submission status

Current
Archive (English)
Archive
   Volumes 81-92
   Volumes 41-60
   Volumes 21-40
   Volumes 1-20
   Volumes 61-80
      Volume 80
      Volume 79
      Volume 78
      Volume 77
      Volume 76
      Volume 75
      Volume 74
      Volume 73
      Volume 72
      Volume 71
      Volume 70
      Volume 69
      Volume 68
      Volume 67
      Volume 66
      Volume 65
      Volume 64
      Volume 63
      Volume 62
      Volume 61
Search
VOLUME 75 | ISSUE 7 | PAGE 407
Density of states in a mesoscopic SNS junction
P. M. Ostrovsky, M. A. Skvortsov, M. V. Feigel'man
L. D. Landau Institute for Theoretical Physics RAS, 117940 Moscow, Russia

PACS: 73.21.-b, 74.50.+r, 74.80.Fp
Abstract
Semiclassical theory of proximity effect predicts a gap E_{g} \sim
\hbar D/L^2 in the excitation spectrum of a long diffusive superconductor/normal-metal/superconductor (SNS) junction. Mesoscopic fluctuations lead to anomalously localized states in the normal part of the junction. As a result, a non-zero, yet exponentially small, density of states (DOS) appears at energies below Eg. In the framework of the supermatrix nonlinear σ-model these prelocalized states are due to instanton configurations with broken supersymmetry. The exact result for the DOS near the semiclassical threshold is found provided the dimensionless conductance of the normal part G_{\rm N} is large. The case of poorly transparent interfaces between the normal and superconductive regions is also considered. In this limit the total number of the subgap states may be large.


Download PS file (GZipped, 104.4K)  |  Download PDF file (240K)