Thermal conductance of a proximity superconductor

TL;DR

This paper investigates heat transport in NSN structures, revealing that the thermal conductance of a short superconductor is significantly increased by the inverse proximity effect, with experimental results aligning with quasiclassical theory.

Contribution

It demonstrates the enhancement of thermal conductance due to inverse proximity effect and identifies a crossover temperature where quasiparticle heat conduction prevails.

Findings

Thermal conductance exceeds BCS predictions in short superconductors.

Experimental data matches quasiclassical diffusive theory.

A crossover temperature for dominant heat conduction mechanisms is identified.

Abstract

We study heat transport in hybrid normal metal - superconductor - normal metal (NSN) structures. We find the thermal conductance of a short superconducting wire to be strongly enhanced beyond the BCS value due to inverse proximity effect. The measurements agree with a model based on the quasiclassical theory of superconductivity in the diffusive limit. We determine a crossover temperature below which quasiparticle heat conduction dominates over the electron-phonon relaxation.