Universal gap fluctuations in the superconductor proximity effect.
Random-matrix theory is used to study the mesoscopic fluctuations of the excitation gap in a metal grain or quantum dot induced by the proximity to a superconductor. We propose that the probability distribution of the gap is a universal function in rescaled units. Our analytical prediction for the gap distribution agrees well with exact diagonalization of a model Hamiltonian.
Vavilov
M G
MG
Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.
Brouwer
P W
PW
Ambegaokar
V
V
Beenakker
C W
CW