2000/08/31 by M. A. Skvortsov, A. I. Larkin, M. V. Feigel'man · 1 citation
Physics and Astronomy · #cond-mat.supr-con #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.63.134507
published as Phys. Rev. B 63, 134507 (2001) · RevTeX, 28 pages, 18 PostScript figures; added and updated references
arxiv created 2000/10/26 · arxiv updated 2009/11/30
We present a general theory of the superconductive proximity effect in disordered normal--superconducting (N-S) structures, based on the recently developed Keldysh action approach. In the case of the absence of interaction in the normal conductor we reproduce known results for the Andreev conductance GA at arbitrary relation between the interface resistance RT and the diffusive resistance RD. In two-dimensional N-S systems, electron-electron interaction in the Cooper channel of normal conductor is shown to strongly affect the value of GA as well as its dependence on temperature, voltage and magnetic field. In particular, an unusual maximum of GA as a function of temperature and/or magnetic field is predicted for some range of parameters RD and RT. The Keldysh action approach makes it possible to calculate the full statistics of charge transfer in such structures. As an application of this method, we calculate the noise power of an N-S contact as a function of voltage, temperature, magnetic field and frequency for arbitrary Cooper repulsion in the normal metal and arbitrary values of the ratio RD/RT.