Open AccessA model for excess Johnson noise in superconducting transition-edge sensors
Author(s) -
Abigail L. Wessels,
Kelsey M. Morgan,
Johnathon D. Gard,
G. C. Hilton,
J. A. B. Mates,
C. D. Reintsema,
Daniel R. Schmidt,
Daniel S. Swetz,
Joel N. Ullom,
Leila R. Vale,
Douglas A. Bennett
Publication year - 2021
Publication title -
applied physics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 442
eISSN - 1077-3118
pISSN - 0003-6951
DOI - 10.1063/5.0043369
Subject(s) - noise (video) , superconductivity , noise power , physics , condensed matter physics , josephson effect , noise temperature , voltage , flicker noise , johnson–nyquist noise , biasing , detector , noise spectral density , burst noise , spectral density , computational physics , optoelectronics , noise measurement , power (physics) , acoustics , noise figure , optics , noise floor , quantum mechanics , phase noise , telecommunications , noise reduction , computer science , cmos , artificial intelligence , image (mathematics) , amplifier
Transition-edge sensors (TESs) are two-dimensional superconducting films utilized as highly sensitive detectors of energy or power. These detectors are voltage biased in the superconducting-normal transition where the film resistance is both finite and a strong function of temperature. Unfortunately, the amount of electrical noise observed in TESs exceeds the predictions of existing noise theories. We describe a possible mechanism for the unexplained excess noise, which we term "mixed-down noise." The source is Johnson noise, which is mixed down to low frequencies by Josephson oscillations in devices with a nonlinear current-voltage relationship. We derive an expression for the power spectral density of this noise and show that its predictions agree with measured data.