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

Superconductor Science and Technology

Impedance measurements on a fast transition-edge sensor for optical and near-infrared range

E. Taralli, Chiara Portesi, L. Lolli, E. Monticone, M. Rajteri, Ilya L. Novikov, Joern Beyer

Published Sep 7, 2010• 20 citations
Publisher

Abstract

Impedance measurements of superconducting transition-edge sensors (TESs) are a powerful tool to obtain information about the TES thermal and electrical properties. We apply this technique to a 20 µm × 20 µm Ti/Au TES, suitable for application in the optical and near-infrared range, and extend the measurements up to 250 kHz in order to obtain a complete frequency response in the complex plane. From these measurements we obtain important thermal and electrical device parameters such as heat capacity C , thermal conductance G and effective thermal time constant τ eff that will be compared with the corresponding values obtained from noise measurements.

DOI
10.1088/0953-2048/23/10/105012

Related papers

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

Fabrication and Characterization of Fast TESs With Small Area for Single Photon Counting

Chiara Portesi, E. Taralli, L. Lolli +2 more

Transition edge sensors (TESs) with high energy resolution (ΔE) at telecommunication wavelengths have been realized in the last years for application to experiments of quantum optics and quantum information. In these fields, lasers with repetition rate of the order of 50 MHz are usually applied and hence TES with recovery times lower than 20 ns would be desirable. To this aim, Ti TESs with area ranging between 1 μm × 1 μm and 2 μm × 2 μm are fabricated and characterized, to study the effects of the different sizes of active areas and critical temperatures on the energy resolutions and on the response times. Titanium TESs have been fabricated by thermal evaporation and Electron Beam Lithography technique on Si/SiN substrates, and they have been electrically and optically characterized. The experimental data have been analyzed and correlated to the detector geometrical parameters. The superconducting transitions of TESs with areas down to 1 μm × 1 μm result to be affected by lateral proximity effects of Nb wirings. Ti TESs with critical temperature of 470 mK show response time of about 150 ns and energy resolution of 0.16 eV.

IEEE Transactions on Applied Superconductivity•Nov 20, 2014•20 citations

Development of Titanium-Based Transition-Edge Single-Photon Detector

Wen Zhang, Yue Geng, Zheng Wang +7 more

Superconducting transition-edge sensors (TESs), working as single-photon detectors with high quantum efficiency, low dark count rate, and photon number resolving capability, have been successfully used in quantum information experiments as well as astronomical transient object observations. Aiming to achieve high count rate, we are developing titanium-based superconducting TES single-photon detectors with a critical temperature of ~300 mK. Ti-based TESs with active area from 10 × 10 μm to 40 × 40 μm are first fabricated on silicon substrate coated with SiOx. The fabricated TES devices show a thermal conductance scaling with the active area and an effective time constant of ~4 μs from pulsed laser diode illumination. In order to get high quantum efficiency, we further design and fabricate a 1550-nm optical cavity based on dielectric mirror and antireflection layer, and study its absorption with an IR spectrometer. Ti TES devices on the dielectric mirror are then fabricated and the superconducting transition is measured.

IEEE Transactions on Applied Superconductivity•Mar 19, 2019•19 citations

A 220 GHz superconducting titanium transition edge sensor array developed for cosmic microwave background experiments

Qianghui Luo, Jiaqiang Zhong, Wei Miao +10 more

Abstract In this paper, we report on the design, fabrication, and characterization of a 220 GHz superconducting transition edge sensor (TES) array developed for ground-based cosmic microwave background (CMB) experiments. Unlike conventional TES arrays adopting thermometers made of bilayer superconducting films, the TES array has thermometers made of simpler single-layer titanium (Ti) film deposited on a suspended silicon nitride (SiN x ) membrane. The thermal weak link is realized by releasing the TES’s thermal island including the Ti thermometer by dry etching with xenon difluoride (XeF2), giving a typical thermal conductance of 25 pW K−1. Its thermal-conductance mechanism is further studied by fitting the measured TES’s complex impedance with a three-block thermal model. The dark and optical noise equivalent power (NEP) of a superconducting TES are both measured. Despite existing lens reflection and dielectric loss in the superconducting microstrip line, its typical optical NEP reaches 100 aW Hz−0.5, which meets the sensitivity requirement for ground-based CMB experiments.

Superconductor Science and Technology•Sep 6, 2023•10 citations

Temperature and current sensitivity extraction of optical superconducting transition-edge sensors based on a two-fluid model*

Yue Geng, Peizhan Li, Jiaqiang Zhong +5 more

Optical superconducting transition-edge sensor (TES) has been widely used in quantum information, biological imaging, and fluorescence microscopy owing to its high quantum efficiency, low dark count, and photon number resolving capability. The temperature sensitivity (αI ) and current sensitivity (βI ) are important parameters for optical TESs, which are generally extracted from the complex impedance. Here we present a method to extract αI and βI based on a two-fluid model and compare the calculated current–voltage curves, pulse response, and theoretical energy resolution with the measured ones. This method shows qualitative agreement that is suitable for further optimization of optical TESs.

Chinese Physics B•Jul 7, 2021•3 citations

An optical transition-edge sensor with high energy resolution

K. Hattori, Toshio Konno, Yoshitaka Miura +2 more

Abstract Optical transition-edge sensors (TESs) have shown an energy resolution for resolving the number of incident photons at the telecommunication wavelength. However, a higher energy resolution is required for biological imaging and microscopic spectroscopy. In this study, we tested an Au/Ti (10/20 nm) bilayer TES that showed a high energy resolution. The high energy resolution was achieved by lowering the critical temperature T c to 115 mK, and the resultant energy resolution was 67 meV full width at half maximum (FWHM) at 0.8 eV. When T c was reduced to 115 mK, the theoretical resolution would scale up to 30 meV FWHM, considering that the typical energy resolution of optical TESs was 150 meV and T c was 300 mK. To investigate the difference between the theoretical expectation (30 meV) and the measured value (67 meV), we measured the complex impedance and current noise of the TES. We found excess Johnson noise in the TES; the excess Johnson noise term M was 1.5 at a bias point where the resistance was 10% of the normal resistance. For reference, the above mentioned TES was compared with a TES showing typical energy resolution (156 meV FWHM). We also discussed factors that improved or inhibited the energy resolution.

arXiv:2204.01903•Superconductor Science and Technology•Jul 5, 2022•39 citations
Impedance measurements of superconducting transition-edge sensors (TESs) are a powerful tool to obtain information about the TES thermal and electrical properties. We apply this technique to a 20 µm × 20 µm Ti/Au TES, suitable for application in the optical and near-infrared range, and extend the measurements up to 250 kHz in order to obtain a complete frequency response in the complex plane. From these measurements we obtain important thermal and electrical device parameters such as heat capacity C , thermal conductance G and effective thermal time constant τ eff that will be compared with the corresponding values obtained from noise measurements.
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.
Transition edge sensors (TESs) with high energy resolution (ΔE) at telecommunication wavelengths have been realized in the last years for application to experiments of quantum optics and quantum information. In these fields, lasers with repetition rate of the order of 50 MHz are usually applied and hence TES with recovery times lower than 20 ns would be desirable. To this aim, Ti TESs with area ranging between 1 μm × 1 μm and 2 μm × 2 μm are fabricated and characterized, to study the effects of the different sizes of active areas and critical temperatures on the energy resolutions and on the response times. Titanium TESs have been fabricated by thermal evaporation and Electron Beam Lithography technique on Si/SiN substrates, and they have been electrically and optically characterized. The experimental data have been analyzed and correlated to the detector geometrical parameters. The superconducting transitions of TESs with areas down to 1 μm × 1 μm result to be affected by lateral proximity effects of Nb wirings. Ti TESs with critical temperature of 470 mK show response time of about 150 ns and energy resolution of 0.16 eV.
Superconducting transition-edge sensors (TESs), working as single-photon detectors with high quantum efficiency, low dark count rate, and photon number resolving capability, have been successfully used in quantum information experiments as well as astronomical transient object observations. Aiming to achieve high count rate, we are developing titanium-based superconducting TES single-photon detectors with a critical temperature of ~300 mK. Ti-based TESs with active area from 10 × 10 μm to 40 × 40 μm are first fabricated on silicon substrate coated with SiOx. The fabricated TES devices show a thermal conductance scaling with the active area and an effective time constant of ~4 μs from pulsed laser diode illumination. In order to get high quantum efficiency, we further design and fabricate a 1550-nm optical cavity based on dielectric mirror and antireflection layer, and study its absorption with an IR spectrometer. Ti TES devices on the dielectric mirror are then fabricated and the superconducting transition is measured.
Abstract In this paper, we report on the design, fabrication, and characterization of a 220 GHz superconducting transition edge sensor (TES) array developed for ground-based cosmic microwave background (CMB) experiments. Unlike conventional TES arrays adopting thermometers made of bilayer superconducting films, the TES array has thermometers made of simpler single-layer titanium (Ti) film deposited on a suspended silicon nitride (SiN x ) membrane. The thermal weak link is realized by releasing the TES’s thermal island including the Ti thermometer by dry etching with xenon difluoride (XeF2), giving a typical thermal conductance of 25 pW K−1. Its thermal-conductance mechanism is further studied by fitting the measured TES’s complex impedance with a three-block thermal model. The dark and optical noise equivalent power (NEP) of a superconducting TES are both measured. Despite existing lens reflection and dielectric loss in the superconducting microstrip line, its typical optical NEP reaches 100 aW Hz−0.5, which meets the sensitivity requirement for ground-based CMB experiments.
Optical superconducting transition-edge sensor (TES) has been widely used in quantum information, biological imaging, and fluorescence microscopy owing to its high quantum efficiency, low dark count, and photon number resolving capability. The temperature sensitivity (αI ) and current sensitivity (βI ) are important parameters for optical TESs, which are generally extracted from the complex impedance. Here we present a method to extract αI and βI based on a two-fluid model and compare the calculated current–voltage curves, pulse response, and theoretical energy resolution with the measured ones. This method shows qualitative agreement that is suitable for further optimization of optical TESs.
Abstract Optical transition-edge sensors (TESs) have shown an energy resolution for resolving the number of incident photons at the telecommunication wavelength. However, a higher energy resolution is required for biological imaging and microscopic spectroscopy. In this study, we tested an Au/Ti (10/20 nm) bilayer TES that showed a high energy resolution. The high energy resolution was achieved by lowering the critical temperature T c to 115 mK, and the resultant energy resolution was 67 meV full width at half maximum (FWHM) at 0.8 eV. When T c was reduced to 115 mK, the theoretical resolution would scale up to 30 meV FWHM, considering that the typical energy resolution of optical TESs was 150 meV and T c was 300 mK. To investigate the difference between the theoretical expectation (30 meV) and the measured value (67 meV), we measured the complex impedance and current noise of the TES. We found excess Johnson noise in the TES; the excess Johnson noise term M was 1.5 at a bias point where the resistance was 10% of the normal resistance. For reference, the above mentioned TES was compared with a TES showing typical energy resolution (156 meV FWHM). We also discussed factors that improved or inhibited the energy resolution.