Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Applied Physics Letters

Thermal fluctuation noise in a voltage biased superconducting transition edge thermometer

Henk F. C. Hoevers, A. Bento, M. P. Bruijn, Luciano G. Gottardi, Marc A. N. Korevaar, Willem A. Mels, Piet A. J. de Korte

Published Dec 25, 2000• 63 citations
Publisher

Abstract

The current noise at the output of a microcalorimeter with a voltage biased superconducting transition edge thermometer is studied in detail. In addition to the two well-known noise sources: thermal fluctuation noise from the heat link to the bath and Johnson noise from the resistive thermometer, a third noise source strongly correlated with the steepness of the thermometer is required to fit the measured noise spectra. Thermal fluctuation noise, originating in the thermometer itself, fully explains the additional noise. A simple model provides quantitative agreement between the observed and calculated noise spectra for all bias points in the superconducting transition.

DOI
10.1063/1.1336550

Related papers

Voltage Fluctuations in ac Biased Superconducting Transition-Edge Sensors

Luciano G. Gottardi, M. de Wit, E. Taralli +2 more

We present a detailed analysis of the fundamental noise sources in superconducting transition-edge sensors (TESs), ac voltage biased at MHz frequencies and treated as superconducting weak links. We have studied the noise in the resistive transition as a function of bath temperature of several detectors with different normal resistances and geometries. We show that the "excess" noise, typically observed in the TES electrical bandwidth, can be explained by the equilibrium Johnson noise of the quasiparticles generated within the weak link. The fluctuations at the Josephson frequency and higher harmonics contribute significantly to the measured voltage noise at the detector bandwidth through the nonlinear response of the weak link with a sinusoidal current-phase relation.

arXiv:2210.06869•Physical Review Letters•May 26, 2021•21 citations

A model for excess Johnson noise in superconducting transition-edge sensors

Abigail L. Wessels, Kelsey M. Morgan, Johnathon D. Gard +8 more

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.

arXiv:1907.11343•Applied Physics Letters•May 17, 2021•18 citations

Model for excess noise in voltage-biased superconducting bolometers

Jan M. Gildemeister, Adrian Tae-Jin Lee, Paul L. Richards

We are developing superconducting transition-edge bolometers for far-infrared and millimeter wavelengths. The bolometers described here are suspended by thin legs of silicon nitride for thermal isolation. At frequencies between 200 mHz and 10-50 Hz these devices show white noise at their thermal fluctuation limit (NEP approximately 10(-17) W/ radicalHz). At higher frequencies a broad peak appears in the noise spectrum, which we attribute to a combination of thermal fluctuations in complex thermal circuits and electrothermal feedback. Detailed noise calculations fit the noise measured in three different devices that were specifically designed to test the model. We discuss how changes in bolometer materials can shift the noise peak above the frequency range of interest for most applications.

Applied Optics•Dec 1, 2001•23 citations

Voltage-biased superconducting transition-edge bolometer with strong electrothermal feedback operated at 370 mK

Shih-Fu Lee, Jan M. Gildemeister, Warren A. Holmes +2 more

We present an experimental study of a composite voltage-biased superconducting bolometer (VSB). The tested VSB consists of a Ti-film superconducting thermometer (T(c) ~375 mK) on a Si substrate suspended by NbTi superconducting leads. A resistor attached to the substrate provides calibrated heat input into the bolometer. The current through the bolometer is measured with a superconducting quantum interference device ammeter. Strong negative electrothermal feedback fixes the bolometer temperature at T(c) and reduces the measured response time from 2.6 s to 13 ms. As predicted, the measured current responsivity of the bolometer is equal to the inverse of the bias voltage. A noise equivalent power of 5 x 10(-17) W/ radicalHz was measured for a thermal conductance G ~ 4.7 x 10(-10) W/K, which is consistent with the expected thermal noise. Excess noise was observed for bias conditions for which the electrothermal feedback strength was close to maximum.

Applied Optics•Jun 1, 1998•95 citations

Complex impedance, responsivity and noise of transition-edge sensors: Analytical solutions for two- and three-block thermal models

Ilari J. Maasilta

The responsivity and noise of a voltage-biased superconducting transition-edge sensor depends strongly on the details of its thermal model, and the simplest theory for TES response assumes a single heat capacity connected to the heat bath. Here, analytical results are derived and discussed for the complex impedance, the responsivity and the noise of a transition-edge sensor, when the thermal model is not simple but consists of either two or three connected heat capacities. The implications of the differences of the models are discussed, as well.

arXiv:1205.5693•AIP Advances•Oct 10, 2012•45 citations

An AC Josephson source for Johnson noise thermometry

Samuel P. Benz, John M. Martinis, Paul D. Dresselhaus +1 more

We have adapted the Josephson arbitrary waveform synthesizer to create a quantized voltage noise source suitable for calibrating the cross-correlation electronics of a Johnson noise thermometer system. The requirements of long term stability and low voltage amplitude allow dramatic simplification of the bias electronics compared to previous circuits. We describe the bias technique and the superconducting integrated circuit used to generate the pseudo-noise waveforms.

Conference on Precision Electromagnetic Measurements•Jun 25, 2003•3 citations
The current noise at the output of a microcalorimeter with a voltage biased superconducting transition edge thermometer is studied in detail. In addition to the two well-known noise sources: thermal fluctuation noise from the heat link to the bath and Johnson noise from the resistive thermometer, a third noise source strongly correlated with the steepness of the thermometer is required to fit the measured noise spectra. Thermal fluctuation noise, originating in the thermometer itself, fully explains the additional noise. A simple model provides quantitative agreement between the observed and calculated noise spectra for all bias points in the superconducting transition.
We present a detailed analysis of the fundamental noise sources in superconducting transition-edge sensors (TESs), ac voltage biased at MHz frequencies and treated as superconducting weak links. We have studied the noise in the resistive transition as a function of bath temperature of several detectors with different normal resistances and geometries. We show that the "excess" noise, typically observed in the TES electrical bandwidth, can be explained by the equilibrium Johnson noise of the quasiparticles generated within the weak link. The fluctuations at the Josephson frequency and higher harmonics contribute significantly to the measured voltage noise at the detector bandwidth through the nonlinear response of the weak link with a sinusoidal current-phase relation.
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.
We are developing superconducting transition-edge bolometers for far-infrared and millimeter wavelengths. The bolometers described here are suspended by thin legs of silicon nitride for thermal isolation. At frequencies between 200 mHz and 10-50 Hz these devices show white noise at their thermal fluctuation limit (NEP approximately 10(-17) W/ radicalHz). At higher frequencies a broad peak appears in the noise spectrum, which we attribute to a combination of thermal fluctuations in complex thermal circuits and electrothermal feedback. Detailed noise calculations fit the noise measured in three different devices that were specifically designed to test the model. We discuss how changes in bolometer materials can shift the noise peak above the frequency range of interest for most applications.
We present an experimental study of a composite voltage-biased superconducting bolometer (VSB). The tested VSB consists of a Ti-film superconducting thermometer (T(c) ~375 mK) on a Si substrate suspended by NbTi superconducting leads. A resistor attached to the substrate provides calibrated heat input into the bolometer. The current through the bolometer is measured with a superconducting quantum interference device ammeter. Strong negative electrothermal feedback fixes the bolometer temperature at T(c) and reduces the measured response time from 2.6 s to 13 ms. As predicted, the measured current responsivity of the bolometer is equal to the inverse of the bias voltage. A noise equivalent power of 5 x 10(-17) W/ radicalHz was measured for a thermal conductance G ~ 4.7 x 10(-10) W/K, which is consistent with the expected thermal noise. Excess noise was observed for bias conditions for which the electrothermal feedback strength was close to maximum.
The responsivity and noise of a voltage-biased superconducting transition-edge sensor depends strongly on the details of its thermal model, and the simplest theory for TES response assumes a single heat capacity connected to the heat bath. Here, analytical results are derived and discussed for the complex impedance, the responsivity and the noise of a transition-edge sensor, when the thermal model is not simple but consists of either two or three connected heat capacities. The implications of the differences of the models are discussed, as well.