Transition-Edge Sensors (TESs) are two-dimensional superconducting films used to detect energy or power. TESs are voltage biased in the resistive transition where the film resistance is both finite and a strong function of temperature. Electrical noise is observed in TESs that exceeds the predictions of existing noise theories. In this manuscript, we describe a model for the unexplained excess noise based on the dynamic resistance of the TES and noise mixed down from frequencies around the Josephson oscillations. We derive an expression for the power spectral density of this noise and show that its predictions match measured data.
@article{arxiv.1907.11343,
title = {A Model for Excess Johnson Noise in Superconducting Transition-edge Sensors},
author = {Abigail Wessels and Kelsey Morgan and Daniel T. Becker and Johnathon D. Gard and Gene C. Hilton and John A. B. Mates and Carl D. Reintsema and Daniel R. Schmidt and Daniel S. Swetz and Joel N. Ullom and Leila R. Vale and Douglas A. Bennett},
journal= {arXiv preprint arXiv:1907.11343},
year = {2024}
}