Andreev Current for low temperature thermometry

TL;DR

This paper demonstrates that disorder-enhanced Andreev current in a normal metal-superconductor tunnel junction can serve as an effective low-temperature thermometer below 200 mK, offering advantages over traditional methods.

Contribution

It introduces a novel low-temperature thermometry technique based on Andreev current, with consistent responsivity and minimal heat conduction, suitable for temperatures below 200 mK.

Findings

Effective measurement of electronic temperature below 200 mK

Advantages over conventional thermometers, including no heat conduction

Constant responsivity across a wide temperature range

Abstract

We demonstrate experimentally that disorder enhanced Andreev current in a tunnel junction between a normal metal and a superconductor provides a method to measure electronic temperature, specifically at temperatures below 200 mK when aluminium is used. This Andreev thermometer has some advantages over conventional quasiparticle thermometers: for instance, it does not conduct heat and its reading does not saturate until at lower temperatures. Another merit is that the responsivity is constant over a wide temperature range.