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

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

Qianghui Luo, Jiaqiang Zhong, Wei Miao, Feiming Li, Qingcheng Wang, Jiang‐Qiao Ding, Feng Wu, Zheng Wang, Kangmin Zhou, Yuan Ren, Wen Zhang, Jing Li, Sheng‐Cai Shi

Published Sep 6, 2023• 10 citations
Publisher

Abstract

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.

DOI
10.1088/1361-6668/acf73b

Related papers

Development of a 220 GHz Ti superconducting TES detector array for CMB polarization experiment

Qianghui LUO, Wei MIAO, Feiming Li +7 more

高灵敏度超导相变边缘探测器（Transition Edge Sensor，TES）在宇宙微波背景（Cosmic Microwave Background，CMB）辐射B模偏振探测方面具有重要的应用前景。本文设计并制备了220 GHz频段8×8像元的天线耦合钛超导TES探测器，实验表征了刻蚀前钛超导TES探测器的低温热导和噪声特性。实验结果显示，钛超导TES探测器低温电声相互作用主导热导约为485.4 pW/K，同时钛超导TES探测器噪声等效功率优于5×10-17 W/Hz0.5。原理上，钛超导TES探测器热导在刻蚀后会进一步减小，理论计算出刻蚀后钛超导TES探测器的热导约为38 pW/K，同时，其热起伏等效噪声功率理论值约为9.2×10-18 W/Hz0.5，因此，钛超导TES探测器在刻蚀后的噪声等效功率性能会进一步提升。

Optics and Precision Engineering•Jan 1, 2023•0 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

Antenna-coupled lumped-element ALD titanium nitride KIDs for CMB instruments (Conference Presentation)

Erik D. Shirokoff, Peter S. Barry, Q. Y. Tang +1 more

Future ground-based cosmic microwave background (CMB) experiments will require more than $10^5$ polarization sensitive pixels covering multiple atmospheric bands. The scientific potential for such an experiment is impressive; however, the technical challenges are daunting: such an instrument will require square meters of focal plane covered in background limited cryogenic detectors and a dramatic increase in readout capability. We are developing novel kinetic inductance detectors (KIDs) optimized for this purpose. These devices use a twin-slot microwave antenna, superconducting Nb transmission line, and a novel coupling scheme that deposits mm-wavelength power onto a high-resistivity meander deposited as the first layer on a bare Si wafer. This architecture allows us to independently adjust the detector and antenna properties and to pursue multi-band designs. We have fabricated superconducting resonators made from atomic layer deposited (ALD) titanium nitride (TiN), with thicknesses ranging from 3 to 40 nm. We find a strong dependence of transition temperature on thickness, from 0.6 to 4.2 K for our thinnest and thickest films, respectively. In dark measurements, we find internal quality factors that range from $10^4$ to $7\times 10^5$ depending on film thickness, and kinetic inductance as high as 8 nH/square. The very small volumes and high kinetic inductance make it possible to engineer extremely sensitive detectors with inductor volumes approaching a few cubic microns that operate at readout frequencies of tens to hundreds of MHz. By taking advantage of the large fractional bandwidth available at low frequencies, we expect to achieve multiplexing densities that exceed that of state of the art TES arrays even without further improvements in film quality factor. We will present the characterization of film properties and dark devices, as well as well as initial optical results for antenna coupled single-band and single-pol devices. We will also discuss designs and sensitivity projections for future dual-pol and multi-band arrays ready for deployment in near-future CMB instruments.

Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XI•Jul 10, 2018•0 citations

Microwave SQUID Multiplexer for Cosmic Microwave Background Imagers

Bradley Dober, Daniel Becker, D. A. Bennett +9 more

Key performance characteristics are demonstrated for the microwave SQUID multiplexer ($\mu$MUX) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the $\mu$MUX produces a white, input referred current noise level of 29~pA$/\sqrt{\mathrm{Hz}}$ at -77~dB microwave probe tone power, which is well below expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure 98~pA$/\sqrt{\mathrm{Hz}}$ in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e., phonon) noise. Furthermore, the power spectral density exhibits a white spectrum at low frequencies ($\sim$~100~mHz), which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the $\mu$MUX as a viable readout technique for future CMB imaging instruments.

•Oct 11, 2017•0 citations

Transition Measurements of a Micron-Sized Transition-Edge Hot-Electron Microbolometer

Emily M. Barrentine, Donald E. Brandl, Ari-David Brown +10 more

We are developing a Transition‐Edge Hot‐electron Microbolometer (THM) for use in large detector array applications in millimeter‐wave astronomy. This bolometer detector consists of a superconducting bilayer TES with an overlapping thin‐film semi‐metal absorber. The detector is deposited directly on the substrate and thermal isolation of the bolometer is controlled by electron‐phonon scattering within the small volume of the detector. We present measurements characterizing the transition behavior of several micron‐sized THM test devices which are optimized for photon‐noise‐limited observations of the Cosmic Microwave Background (CMB). We interpret these measurements in terms of a lateral proximity effect between the TES and the superconducting Nb TES leads. We discuss possible modifications to the THM design to compensate for this effect while retaining the small detector volume necessary to obtain the desired value of electron‐phonon thermal conductivity.

AIP conference proceedings•Jan 1, 2009•2 citations

Microwave SQUID multiplexer demonstration for cosmic microwave background imagers

B. Dober, D. T. Becker, D. A. Bennett +10 more

Key performance characteristics are demonstrated for the microwave SQUID multiplexer (µmux) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the µmux produces a white, input referred current noise level of [Formula: see text] at -77 dB microwave probe tone power, which is well below expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure [Formula: see text] in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e. phonon) noise. Furthermore, the power spectral density is white over a range of frequencies down to ~ 100 mHz, which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the µmux as a viable readout technique for future CMB imaging instruments.

arXiv:1710.04326•Applied Physics Letters•Dec 11, 2017•58 citations
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.
高灵敏度超导相变边缘探测器（Transition Edge Sensor，TES）在宇宙微波背景（Cosmic Microwave Background，CMB）辐射B模偏振探测方面具有重要的应用前景。本文设计并制备了220 GHz频段8×8像元的天线耦合钛超导TES探测器，实验表征了刻蚀前钛超导TES探测器的低温热导和噪声特性。实验结果显示，钛超导TES探测器低温电声相互作用主导热导约为485.4 pW/K，同时钛超导TES探测器噪声等效功率优于5×10-17 W/Hz0.5。原理上，钛超导TES探测器热导在刻蚀后会进一步减小，理论计算出刻蚀后钛超导TES探测器的热导约为38 pW/K，同时，其热起伏等效噪声功率理论值约为9.2×10-18 W/Hz0.5，因此，钛超导TES探测器在刻蚀后的噪声等效功率性能会进一步提升。
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.
Future ground-based cosmic microwave background (CMB) experiments will require more than 10510^5105 polarization sensitive pixels covering multiple atmospheric bands. The scientific potential for such an experiment is impressive; however, the technical challenges are daunting: such an instrument will require square meters of focal plane covered in background limited cryogenic detectors and a dramatic increase in readout capability. We are developing novel kinetic inductance detectors (KIDs) optimized for this purpose. These devices use a twin-slot microwave antenna, superconducting Nb transmission line, and a novel coupling scheme that deposits mm-wavelength power onto a high-resistivity meander deposited as the first layer on a bare Si wafer. This architecture allows us to independently adjust the detector and antenna properties and to pursue multi-band designs. We have fabricated superconducting resonators made from atomic layer deposited (ALD) titanium nitride (TiN), with thicknesses ranging from 3 to 40 nm. We find a strong dependence of transition temperature on thickness, from 0.6 to 4.2 K for our thinnest and thickest films, respectively. In dark measurements, we find internal quality factors that range from 10410^4104 to 7×1057\times 10^57×105 depending on film thickness, and kinetic inductance as high as 8 nH/square. The very small volumes and high kinetic inductance make it possible to engineer extremely sensitive detectors with inductor volumes approaching a few cubic microns that operate at readout frequencies of tens to hundreds of MHz. By taking advantage of the large fractional bandwidth available at low frequencies, we expect to achieve multiplexing densities that exceed that of state of the art TES arrays even without further improvements in film quality factor. We will present the characterization of film properties and dark devices, as well as well as initial optical results for antenna coupled single-band and single-pol devices. We will also discuss designs and sensitivity projections for future dual-pol and multi-band arrays ready for deployment in near-future CMB instruments.
Key performance characteristics are demonstrated for the microwave SQUID multiplexer (μ\muμMUX) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the μ\muμMUX produces a white, input referred current noise level of 29~pA/Hz/\sqrt{\mathrm{Hz}}/Hz​ at -77~dB microwave probe tone power, which is well below expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure 98~pA/Hz/\sqrt{\mathrm{Hz}}/Hz​ in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e., phonon) noise. Furthermore, the power spectral density exhibits a white spectrum at low frequencies (∼\sim∼~100~mHz), which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the μ\muμMUX as a viable readout technique for future CMB imaging instruments.
We are developing a Transition‐Edge Hot‐electron Microbolometer (THM) for use in large detector array applications in millimeter‐wave astronomy. This bolometer detector consists of a superconducting bilayer TES with an overlapping thin‐film semi‐metal absorber. The detector is deposited directly on the substrate and thermal isolation of the bolometer is controlled by electron‐phonon scattering within the small volume of the detector. We present measurements characterizing the transition behavior of several micron‐sized THM test devices which are optimized for photon‐noise‐limited observations of the Cosmic Microwave Background (CMB). We interpret these measurements in terms of a lateral proximity effect between the TES and the superconducting Nb TES leads. We discuss possible modifications to the THM design to compensate for this effect while retaining the small detector volume necessary to obtain the desired value of electron‐phonon thermal conductivity.
Key performance characteristics are demonstrated for the microwave SQUID multiplexer (µmux) coupled to transition edge sensor (TES) bolometers that have been optimized for cosmic microwave background (CMB) observations. In a 64-channel demonstration, we show that the µmux produces a white, input referred current noise level of [Formula: see text] at -77 dB microwave probe tone power, which is well below expected fundamental detector and photon noise sources for a ground-based CMB-optimized bolometer. Operated with negligible photon loading, we measure [Formula: see text] in the TES-coupled channels biased at 65% of the sensor normal resistance. This noise level is consistent with that predicted from bolometer thermal fluctuation (i.e. phonon) noise. Furthermore, the power spectral density is white over a range of frequencies down to ~ 100 mHz, which enables CMB mapping on large angular scales that constrain the physics of inflation. Additionally, we report cross-talk measurements that indicate a level below 0.3%, which is less than the level of cross-talk from multiplexed readout systems in deployed CMB imagers. These measurements demonstrate the µmux as a viable readout technique for future CMB imaging instruments.