We present a set of experiments to optimize the performance of the noninvasive thermometer based on proximity superconductivity. Current through a standard tunnel junction between an aluminum superconductor and a copper electrode is controlled by the strength of the proximity induced to this normal metal, which in turn is determined by the position of a direct superconducting contact from the tunnel junction. Several devices with different distances were tested. We develop a theoretical model based on Usadel equations and dynamic Coulomb blockade which reproduces the measured results and yields a tool to calibrate the thermometer and to optimize it further in future experiments.
@article{arxiv.1911.02844,
title = {Optimized proximity thermometer for ultra-sensitive detection},
author = {Bayan Karimi and Danilo Nikolic and Tuomas Tuukkanen and Joonas T. Peltonen and Wolfgang Belzig and Jukka P. Pekola},
journal= {arXiv preprint arXiv:1911.02844},
year = {2020}
}