Theory of temperature fluctuation statistics in superconductor-normal metal tunnel structures

TL;DR

This paper develops a theoretical framework for understanding temperature fluctuation statistics in superconductor-normal metal tunnel structures, highlighting conditions for non-Gaussian behavior and proposing measurement methods.

Contribution

It provides a detailed analysis of temperature fluctuation regimes in SINIS structures, including non-Gaussian effects and their impact on current fluctuations.

Findings

Identification of conditions for non-Gaussian temperature fluctuations

Analysis of current fluctuations caused by temperature variability

Proposal of a measurement setup for observing fluctuations

Abstract

We describe the statistics of temperature fluctuations in a SINIS structure, where a normal metal island (N) is coupled by tunnel junctions (I) to two superconducting leads (S). We specify conditions under which this structure exhibits manifestly non-Gaussian fluctuations of temperature. We consider both the Gaussian and non-Gaussian regimes of these fluctuations, and the current fluctuations that are caused by the fluctuating temperature. We also describe a measurement setup that could be used to observe the temperature fluctuations.