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A Model for Excess Johnson Noise in Superconducting Transition-edge Sensors



Abigail Wessels, Kelsey Morgan, Dan Becker, Johnathon Gard, Gene C. Hilton, John Mates, Carl D. Reintsema, Dan Schmidt, Daniel Swetz, Joel Ullom, Leila R. Vale, Douglas Bennett


Transition-Edge Sensors (TESs) are two-dimensional superconducting films used to detect energy or power. These detectors are voltage biased in the superconducting 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 possible mechanism for the unexplained excess noise, which we will call mixed-down noise. The source is Johnson noise which is mixed down to low frequencies by Josephson oscillations in a device 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.
Applied Physics Letters


Wessels, A. , Morgan, K. , Becker, D. , Gard, J. , Hilton, G. , Mates, J. , Reintsema, C. , Schmidt, D. , Swetz, D. , Ullom, J. , Vale, L. and Bennett, D. (2021), A Model for Excess Johnson Noise in Superconducting Transition-edge Sensors, Applied Physics Letters, [online], (Accessed April 23, 2024)
Created May 18, 2021, Updated January 27, 2023