Noninvasive Thermometer Based on the Zero-Bias Anomaly of a Superconducting Junction for Ultrasensitive Calorimetry

Abstract

The authors present a highly noninvasive and fast nanoscale thermometer that outperforms those in common use. It is based on the superconducting proximity effect of a normal metal, yielding a temperature-dependent zero-bias anomaly (ZBA) in charge transport. Operating at very low temperatures, it opens the way to calorimetry at ultralow energies, and a road map for detecting single microwave quanta.