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

IEEE Transactions on Applied Superconductivity

Study of Excess Heat Capacity and Suppressed Kapitza Conductance in TES Devices

Yue Zhao, John W. Appel, James A. Chervenak, William Bertrand Doriese, Suzanne T. Staggs

Published Jan 10, 2011• 7 citations
Publisher

Abstract

A number of groups have produced TES bolometers and other devices using dielectric membranes for thermal isolation in which excess heat capacity is reported. We have fabricated a series of TES devices using large area membranes and narrow legs for thermal isolation to study the scaling of intrinsic parameters like the heat capacity of the membrane. The devices are arranged on a single chip to ensure similarity of devices parameters (i.e., film thicknesses) and processing history. Measurements (non-multiplexed) of the current-voltage characteristic and complex impedance are made using a well-characterized, highly uniform, multichannel SQUID setup. We have developed model for non-ideal transition edge sensor performance that enables extraction of heat capacities and thermal conductances identified in the models. We report on the magnitude of excess heat capacity in the dielectric membrane and thermal conductance of the metal-to-dielectric interface in each of the designs.

DOI
10.1109/tasc.2010.2097231

Related papers

Unraveling Current-Bias-Induced Transition Discrepancy in Transition-Edge Sensors in R-T Tests and Establishing a Reliable Characterizing Method

Qing Yu, Yongping Li, Guanhua Gao +7 more

Understanding the weak thermal links in supporting legs of transition edge sensors (TES) is crucial for developing highly sensitive bolometers used in cosmic microwave background (CMB) detection. Conventional current-biased differential resistance measurements under varying temperature (R-T) used to characterizeRand critical temperature (Tc) of TES often encounter a phenomenon: the bias current will affect the transition temperature obtained duringTbdrop testing, as well as affect the obtained shape of the transition region. This behavior stems from the weak thermal links of TES under current bias, limitingR-Tmeasurements to only rough information about the TES transition regime sometimes. The detailed and accurate performance parameters typically relying on voltage-biased current-voltageI-Vmeasurements using using superconducting quantum interference devices (SQUIDs). In fact, the positive electro-thermal feedback induced by current bias contains valuable insights into the device's intrinsic properties. This work focuses on elaborating this underlying mechanism: by analyzing the current-induced suppression of measured transition temperature inR-Tmeasurements, we extract key parameters including thermal conductance (G), thermal exponent (n),Tc, and saturation power (Psat). This study provides intuitive calculations and visualizations of the electro-thermal behaviors induced by current bias in TES devices, and offers a simple and rapid complementary tool for electro-thermal parameter extraction. In batch TES fabrication, it can serve as a pre-screening tool to improve the efficiency of subsequent high-precision SQUID-basedI-Vcharacterization.

IEEE Transactions on Applied Superconductivity•Feb 16, 2026•0 citations

Characterization of Silicon-Membrane TES Microcalorimeters for Large-Format X-ray Spectrometers with Integrated Microwave SQUID Readout

Avirup Roy, Robinjeet Singh, Joel C. Weber +17 more

We present the electro-thermal characterization of transition-edge sensor (TES) detectors suspended on Si membranes fabricated using a silicon-on-insulator (SOI) wafer. The use of an all-silicon fabrication platform, in contrast to the more commonly used silicon nitride membranes, is compatible with monolithic fabrication of integrated TES and SQUID circuits. The all-silicon architecture additionally allows efficient use of focal plane area; the readout circuitry may be positioned out of the focal plane by bending a thinned portion of the chip. Compatibility with integrated fabrication and efficient use of focal plane area provide a path to an efficient soft X-ray spectrometer. This work is motivated by our goal to develop a 10,000-pixel TES spectrometer to overcome critical measurement limitations in catalysis research. The characterization of fragile, carbon-based intermediates via techniques like Resonant Inelastic X-ray Scattering (RIXS) is often precluded by the slow, high-flux nature of existing technologies. The new instrument will allow for fast RIXS measurements to be made without causing sample damage. We verify the detector models and measure the energy resolution using a pulsed optical laser, demonstrating the viability of this approach for the final instrument to be deployed at the National Synchrotron Light Source II (NSLS-II).

physics.ins-detCross-listedarXiv:2601.09629•Jan 15, 2026

Relationships Between Complex Impedance, Thermal Response, and Noise in TES Calorimeters and Bolometers

M. A. Lindeman, Bob P. F. Dirks, Jan van der Kuur +6 more

Complex impedance measurements are widely used to characterize superconducting transition edge sensors (TESs) in bolometers and microcalorimeters. Typically, models are fit to impedance data to find parameters which pertain to the performance of these detectors. After the parameters are determined, the models are then used to compute the response and noise of these devices. In this paper, we present general relationships between the measured impedance, the thermal response to power in the TES, and noise. We describe a method for measuring αIand βIof the superconducting phase transition, which does not require model fitting. We find bolometer response is determined from the impedance provided that the absorber is strongly coupled to the TES electron system. We also demonstrate how to calculate upper and lower limits on the noise directly from the impedance data without modeling. Additionally, the relations can be used to check the validity of the models and to understand what information can and cannot be obtained from measurements of impedance, response, and noise.

IEEE Transactions on Applied Superconductivity•Jan 7, 2011•12 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

Demonstration of a Pixel-Scale Superconducting Heat Switch for an Ideal Integrating Bolometer

Edgar R. Canavan, Thomas R. Stevenson, Peter C. Nagler +1 more

The sensitivity of a bolometer is in principle limited by the phonon noise, which is a function of the conductance between its absorber and the thermal sink. However, practical issues limit the degree to which conductance can be minimized. For example, in a high-radiation environment, extremely low conductance, or, equivalently, long thermal recovery time, can lead to high data loss. To circumvent such limitations, we are developing a technique of modulating the conductance through the use of pixel-scale superconducting heat switches. We have fabricated bolometer-like test devices consisting of isolated regions connected to a thermal ground plane through narrow aluminum strips. Niobium coils are patterned around the aluminum strips. Flowing current through a coil allows the aluminum to be driven into the normal or high thermal conductance state. We have measured the conductance of these devices as a function of temperature and drive coil current.

IEEE Transactions on Applied Superconductivity•Feb 7, 2017•3 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
A number of groups have produced TES bolometers and other devices using dielectric membranes for thermal isolation in which excess heat capacity is reported. We have fabricated a series of TES devices using large area membranes and narrow legs for thermal isolation to study the scaling of intrinsic parameters like the heat capacity of the membrane. The devices are arranged on a single chip to ensure similarity of devices parameters (i.e., film thicknesses) and processing history. Measurements (non-multiplexed) of the current-voltage characteristic and complex impedance are made using a well-characterized, highly uniform, multichannel SQUID setup. We have developed model for non-ideal transition edge sensor performance that enables extraction of heat capacities and thermal conductances identified in the models. We report on the magnitude of excess heat capacity in the dielectric membrane and thermal conductance of the metal-to-dielectric interface in each of the designs.
Understanding the weak thermal links in supporting legs of transition edge sensors (TES) is crucial for developing highly sensitive bolometers used in cosmic microwave background (CMB) detection. Conventional current-biased differential resistance measurements under varying temperature (R-T) used to characterizeRand critical temperature (Tc) of TES often encounter a phenomenon: the bias current will affect the transition temperature obtained duringTbdrop testing, as well as affect the obtained shape of the transition region. This behavior stems from the weak thermal links of TES under current bias, limitingR-Tmeasurements to only rough information about the TES transition regime sometimes. The detailed and accurate performance parameters typically relying on voltage-biased current-voltageI-Vmeasurements using using superconducting quantum interference devices (SQUIDs). In fact, the positive electro-thermal feedback induced by current bias contains valuable insights into the device's intrinsic properties. This work focuses on elaborating this underlying mechanism: by analyzing the current-induced suppression of measured transition temperature inR-Tmeasurements, we extract key parameters including thermal conductance (G), thermal exponent (n),Tc, and saturation power (Psat). This study provides intuitive calculations and visualizations of the electro-thermal behaviors induced by current bias in TES devices, and offers a simple and rapid complementary tool for electro-thermal parameter extraction. In batch TES fabrication, it can serve as a pre-screening tool to improve the efficiency of subsequent high-precision SQUID-basedI-Vcharacterization.
We present the electro-thermal characterization of transition-edge sensor (TES) detectors suspended on Si membranes fabricated using a silicon-on-insulator (SOI) wafer. The use of an all-silicon fabrication platform, in contrast to the more commonly used silicon nitride membranes, is compatible with monolithic fabrication of integrated TES and SQUID circuits. The all-silicon architecture additionally allows efficient use of focal plane area; the readout circuitry may be positioned out of the focal plane by bending a thinned portion of the chip. Compatibility with integrated fabrication and efficient use of focal plane area provide a path to an efficient soft X-ray spectrometer. This work is motivated by our goal to develop a 10,000-pixel TES spectrometer to overcome critical measurement limitations in catalysis research. The characterization of fragile, carbon-based intermediates via techniques like Resonant Inelastic X-ray Scattering (RIXS) is often precluded by the slow, high-flux nature of existing technologies. The new instrument will allow for fast RIXS measurements to be made without causing sample damage. We verify the detector models and measure the energy resolution using a pulsed optical laser, demonstrating the viability of this approach for the final instrument to be deployed at the National Synchrotron Light Source II (NSLS-II).
Complex impedance measurements are widely used to characterize superconducting transition edge sensors (TESs) in bolometers and microcalorimeters. Typically, models are fit to impedance data to find parameters which pertain to the performance of these detectors. After the parameters are determined, the models are then used to compute the response and noise of these devices. In this paper, we present general relationships between the measured impedance, the thermal response to power in the TES, and noise. We describe a method for measuring αIand βIof the superconducting phase transition, which does not require model fitting. We find bolometer response is determined from the impedance provided that the absorber is strongly coupled to the TES electron system. We also demonstrate how to calculate upper and lower limits on the noise directly from the impedance data without modeling. Additionally, the relations can be used to check the validity of the models and to understand what information can and cannot be obtained from measurements of impedance, response, and noise.
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.
The sensitivity of a bolometer is in principle limited by the phonon noise, which is a function of the conductance between its absorber and the thermal sink. However, practical issues limit the degree to which conductance can be minimized. For example, in a high-radiation environment, extremely low conductance, or, equivalently, long thermal recovery time, can lead to high data loss. To circumvent such limitations, we are developing a technique of modulating the conductance through the use of pixel-scale superconducting heat switches. We have fabricated bolometer-like test devices consisting of isolated regions connected to a thermal ground plane through narrow aluminum strips. Niobium coils are patterned around the aluminum strips. Flowing current through a coil allows the aluminum to be driven into the normal or high thermal conductance state. We have measured the conductance of these devices as a function of temperature and drive coil current.
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.