Effects of charging energy on SINIS tunnel junction thermometry

TL;DR

This paper theoretically examines how charging energy influences the performance of NIS tunnel junction thermometers, revealing that charging effects alter voltage-temperature response and can be modulated via a gate electrode.

Contribution

It provides a numerical analysis of charging energy effects on NIS thermometry and demonstrates responsivity modulation through a gate electrode.

Findings

Charging effects modify the voltage-temperature response.

Responsivity can be maximized with a closed gate.

Charging effects can be controlled to optimize thermometer performance.

Abstract

We have investigated theoretically the effects of the charging energy to the normal metal--insulator--superconductor (NIS) tunnel junction used as a thermometer. We demonstrate by numerical calculations how the charging effects modify NIS thermometry, and how the voltage--to--temperature response and the responsivity $|dV/dT|$ of a current biased thermometer are affected. In addition, we show that the responsivity of the thermometer can be modulated with an additional gate electrode. The maximum responsivity is achieved when the Coulomb blockade is maximal, i.e. with a closed gate.