Quantitative measurements of the thermal resistance of Andreev interferometers

TL;DR

This study quantitatively measures the thermal resistance of diffusive Andreev interferometers, revealing flux-dependent oscillations and deviations from theoretical predictions, thus advancing understanding of phase-coherent thermal transport.

Contribution

First direct quantitative measurement of thermal resistance in diffusive Andreev interferometers using local thermometry techniques.

Findings

Thermal resistance $R^T$ is strongly enhanced at low temperatures.

$R^T$ oscillates with magnetic flux with a period of one flux quantum.

Measured $R^T$ exceeds predictions from recent simulations.

Abstract

Using a local thermometry technique, we have been able to quantitatively measure the thermal resistance $R^T$ of diffusive Andreev interferometers. We find that $R^T$ is strongly enhanced from its normal state value at low temperatures, and behaves non-linearly as a function of the thermal current through the sample. We also find that the $R^T$ oscillates as a function of magnetic flux with a fundamental period corresponding to one flux quantum $\Phi_0=h/2e$, demonstrating the phase coherent nature of thermal transport in these devices. The magnitude of $R^T$ is larger than predicted by recent numerical simulations.