Thermoelectric effects in superconducting proximity structures

TL;DR

This paper reviews thermoelectric effects in superconductor-normal metal proximity structures, highlighting how supercurrents influence electron energy distributions and induce thermoelectric phenomena even with electron-hole symmetry.

Contribution

It provides a comprehensive review of thermoelectric effects in superconducting proximity structures using the dirty-limit quasiclassical theory.

Findings

Supercurrents can tune local electron energy distributions.

Finite thermoelectric effects occur despite electron-hole symmetry.

Existing observations can be explained by the theory.

Abstract

Attaching a superconductor in good contact with a normal metal makes rise to a proximity effect where the superconducting correlations leak into the normal metal. An additional contact close to the first one makes it possible to carry a supercurrent through the metal. Forcing this supercurrent flow along with an additional quasiparticle current from one or many normal-metal reservoirs makes rise to many interesting effects. The supercurrent can be used to tune the local energy distribution function of the electrons. This mechanism also leads to finite thermoelectric effects even in the presence of electron-hole symmetry. Here we review these effects and discuss to which extent the existing observations of thermoelectric effects in metallic samples can be explained through the use of the dirty-limit quasiclassical theory.