Nonequilibrium and proximity effects in superconductor–normal metal junctions

Abstract

We study the consequences of nonequilibrium heating and inverse proximity effect in normal metal--insulator--superconductor--insulator--normal metal (NISIN) junctions with a simple quasi-one-dimensional model. We especially focus on observables and parameter regions that are of interest in the design of SINIS coolers with quasiparticle traps. We present numerical results calculated by solving the Usadel equation and also present analytical approximations in two limiting cases: a short junction with a non-negligible resistance in both ends and a long junction with a transparent contact at one end.