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

Development of a Zappe-interferometer style superconducting switch for time-division multiplexed readout of transition edge sensor array

Taiyu Li, Yuanxing Xu, Chaoqun Wang, Lihong Tang, Huanqian Zhang, Hangxing Xie, Liliang Ying, Lixing You, Bo Gao, Zhen Wang

Published Sep 26, 2024• 3 citations
Publisher

Abstract

Abstract Time-division multiplexing constitutes a pivotal readout technique for arrays of transition edge sensors (TES). At the heart of constructing the multiplexing unit (Mux unit) lies a flux-actuated superconducting switch. The superconducting quantum interference device (SQUID) is ideally suited for this role due to its compatibility with the fabrication processes of the SQUID current amplifier, which is employed to read the TES signal. This compatibility facilitates the integration of the switches with the SQUID amplifiers on a single chip. Nevertheless, the critical current of a switch based on a conventional DC-SQUID exhibits abrupt changes with the control flux near the local minimum of the threshold curve, which is the typical operating point of the SQUID amplifier. Such abrupt changes compromise the stability of the SQUID amplifier’s operational point. To mitigate this issue, a Zappe interferometer-style switch design has been adopted, providing a threshold curve with a more pronounced flat region. In this work, we present the design and characterization of Zappe-style switches and demonstrate the operational efficacy of the Mux unit.

DOI
10.1088/1361-6668/ad803f

Related papers

Dynamic behavior of dc SQUIDs in time-division multiplexing readout schemes

Erik Heinz, V. Zakosarenko, T. May +1 more

We have investigated the transient response of superconducting quantum interference devices (SQUIDs) used in time-division multiplexing schemes for the readout from arrays of superconducting transition-edge sensors (TES). In time-division multiplexing the per channel settling time is an important parameter since it limits the multiplexing frequency as well as the signal-to-noise ratio. Although SQUIDs in general are fast cryoelectronic devices operating at a nanosecond scale, experimental evidence shows that the settling time in bias-switched SQUID multiplexers can, in the case of a low impedance input circuit, reach several microseconds. We have confirmed this behavior through numerical transient analysis using a Josephson circuit simulator. Within the simulation we have found that the transient response can be reduced using an extra inductor in series with the input coil of the dc SQUID. This result in turn has been confirmed experimentally. We furthermore discuss the conflicting constraints that a desired high signal bandwidth places on the parameters of the multiplexer, the readout SQUIDs, and the TES.

Superconductor Science and Technology•Mar 7, 2013•9 citations

Code-division multiplexing of superconducting transition-edge sensor arrays

K. D. Irwin, Michael D. Niemack, Joern Beyer +7 more

Multiplexed superconducting quantum interference device (SQUID) amplifiers have recently enabled the deployment of kilopixel arrays of superconducting transition-edge sensor (TES) detectors on a variety of receivers for astrophysics. Existing multiplexing techniques for TES arrays, however, have constraints due to aliasing of SQUID noise, the size of the required filtering elements, or the complexity of the room-temperature electronics that make it difficult to scale to much larger arrays. We have developed a Walsh code-division SQUID multiplexer that has the potential to enable the multiplexing of larger arrays or pixels with faster thermal response times. The multiplexer uses superconducting switches to modulate the polarity of coupling between N individual TES detectors and a single output SQUID channel. The polarities of the detector signals are switched in the pattern of an N × N Walsh matrix, so a frame composed of N orthogonal samples can be used to reconstruct the detector signals without degradation. We present an analysis of the circuit architecture and preliminary results.

Superconductor Science and Technology•Feb 22, 2010•60 citations

Multiplexing technology based on SQUID for readout of superconducting transition-edge sensor arrays

Xinyu Wu, Qing Yu, Yongcheng He +2 more

Multiplexing technologies based on superconducting quantum interference devices (SQUIDs) are crucial to cryogenic readout of superconducting transition-edge sensor (TES) arrays. Demands for large-scale TES arrays promote the development of multiplexing technologies towards large multiplexing factors and low readout noise. The development of multiplexing technologies also facilitates new applications of TES arrays in a wide range of frequencies. Here we summarize different types of SQUID-based multiplexing technologies including time-division multiplexing, code-division multiplexing, frequency-division multiplexing and microwave SQUID multiplexing. The advances and parameter constraints of each multiplexing technology are also discussed.

Chinese Physics B•Apr 22, 2022•6 citations

Cryogenic time-domain multiplexer based on SQUID arrays and superconducting/normal conducting switches

Nikolai Beev, M. Kiviranta, Jan van der Kuur +7 more

We have demonstrated the operation of a 12-channel Beyer-style SQUID-based time domain multiplexer. It was manufactured using a fabrication process that is cross-compatible between VTT and IPHT-Jena. The multiplexer consists of twelve 12-SQUID series arrays, each shunted by a Zappe-style interferometer array acting as a flux-controlled superconducting/normal conducting switch. By keeping all switches but one in the superconducting state, it is possible to select one active readout channel at a time. A flux feedback coil common to all SQUID arrays allows realization of a flux-locked loop. We present characteristics of the multiplexer and measurement data from experiments with a 25-pixel X-ray calorimeter array operated at T < 100 mK in a dilution refrigerator.

Journal of Physics Conference Series•May 12, 2014•4 citations

Development of a microwave SQUID multiplexer for superconducting transition-edge sensor bolometer arrays

Zhi-Fa Feng, Xian-Feng Zhou, M Y Li +10 more

Abstract A microwave SQUID multiplexer ( μ MUX) with a high multiplexing factor is a promising readout approach for large-scale superconducting transition-edge sensor (TES) bolometer arrays. This paper reports on the characteristics of 16-channel μ MUX prototype chips and a 60-channel readout module developed to read out TES bolometers for the Ali cosmic microwave background polarization telescope (AliCPT). We designed two different coupling structures between the resonator and the radio-frequency superconducting interference device: design A with a mutual inductance ( M T ) of 2.3 pH and design B with an M T of 6.5 pH. For design A, the mean resonator bandwidth ( Δ f BW ) and peak-to-peak frequency shift ( Δ f pp ) are approximately 610 kHz and 290 kHz, respectively. The measured mean open-loop current noise is less than 40 pA / Hz . Preliminary results indicate that crosstalk between adjacent channels is below 1% in our design A μ MUX chip. A measured channel with design B shows a Δ f BW of 586 kHz and a current noise of 33 pA / Hz , similar to the design A channels. In comparison, the Δ f pp of 803 kHz is much larger than the design A channels due to a larger M T . The readout module, consisting of two design A chips and two design B chips, shows 60 resonances, corresponding to a yield of 94%. In the future, we will place 32 design A channels within the same chip dimension to increase the channel density and build a larger readout module suitable for AliCPT TES arrays.

Superconductor Science and Technology•Sep 1, 2026•0 citations

A frequency-domain SQUID multiplexer for arrays of transition-edge superconducting sensors

Trevor M. Lanting, Hsiao-Mei Cho, John L. Clarke +5 more

We describe the development of a frequency-domain multiplexer (MUX) to read out arrays of superconducting transition-edge sensors (TES). Fabrication of large-format arrays of these sensors is becoming practical; however, reading out each sensor in the array is a major instrumental challenge. Frequency-domain multiplexing can greatly simplify the instrumentation of large arrays by reducing the number of SQUID's (superconducting quantum interference devices) and wires to the low temperature stages. Each sensor is AC biased at a different frequency, ranging from 380 kHz to 1 MHz. Each sensor signal amplitude-modulates its respective AC bias frequency. An LC filter associated with each sensor suppresses Johnson noise from the other sensors. The signals are combined at a current summing node and measured by a single SQUID. The individual signals from each sensor are then lock-in detected by room temperature electronics. Test chips with fully lithographed LC filters for up to 32 channels have been designed and fabricated. The capacitance and inductance values have been measured and are close to the design goals. We discuss the basic principles of frequency-domain multiplexing, the design and testing of the test chips, and the implementation of a practical system.

IEEE Transactions on Applied Superconductivity•Jun 1, 2003•20 citations
Abstract Time-division multiplexing constitutes a pivotal readout technique for arrays of transition edge sensors (TES). At the heart of constructing the multiplexing unit (Mux unit) lies a flux-actuated superconducting switch. The superconducting quantum interference device (SQUID) is ideally suited for this role due to its compatibility with the fabrication processes of the SQUID current amplifier, which is employed to read the TES signal. This compatibility facilitates the integration of the switches with the SQUID amplifiers on a single chip. Nevertheless, the critical current of a switch based on a conventional DC-SQUID exhibits abrupt changes with the control flux near the local minimum of the threshold curve, which is the typical operating point of the SQUID amplifier. Such abrupt changes compromise the stability of the SQUID amplifier’s operational point. To mitigate this issue, a Zappe interferometer-style switch design has been adopted, providing a threshold curve with a more pronounced flat region. In this work, we present the design and characterization of Zappe-style switches and demonstrate the operational efficacy of the Mux unit.
We have investigated the transient response of superconducting quantum interference devices (SQUIDs) used in time-division multiplexing schemes for the readout from arrays of superconducting transition-edge sensors (TES). In time-division multiplexing the per channel settling time is an important parameter since it limits the multiplexing frequency as well as the signal-to-noise ratio. Although SQUIDs in general are fast cryoelectronic devices operating at a nanosecond scale, experimental evidence shows that the settling time in bias-switched SQUID multiplexers can, in the case of a low impedance input circuit, reach several microseconds. We have confirmed this behavior through numerical transient analysis using a Josephson circuit simulator. Within the simulation we have found that the transient response can be reduced using an extra inductor in series with the input coil of the dc SQUID. This result in turn has been confirmed experimentally. We furthermore discuss the conflicting constraints that a desired high signal bandwidth places on the parameters of the multiplexer, the readout SQUIDs, and the TES.
Multiplexed superconducting quantum interference device (SQUID) amplifiers have recently enabled the deployment of kilopixel arrays of superconducting transition-edge sensor (TES) detectors on a variety of receivers for astrophysics. Existing multiplexing techniques for TES arrays, however, have constraints due to aliasing of SQUID noise, the size of the required filtering elements, or the complexity of the room-temperature electronics that make it difficult to scale to much larger arrays. We have developed a Walsh code-division SQUID multiplexer that has the potential to enable the multiplexing of larger arrays or pixels with faster thermal response times. The multiplexer uses superconducting switches to modulate the polarity of coupling between N individual TES detectors and a single output SQUID channel. The polarities of the detector signals are switched in the pattern of an N × N Walsh matrix, so a frame composed of N orthogonal samples can be used to reconstruct the detector signals without degradation. We present an analysis of the circuit architecture and preliminary results.
Multiplexing technologies based on superconducting quantum interference devices (SQUIDs) are crucial to cryogenic readout of superconducting transition-edge sensor (TES) arrays. Demands for large-scale TES arrays promote the development of multiplexing technologies towards large multiplexing factors and low readout noise. The development of multiplexing technologies also facilitates new applications of TES arrays in a wide range of frequencies. Here we summarize different types of SQUID-based multiplexing technologies including time-division multiplexing, code-division multiplexing, frequency-division multiplexing and microwave SQUID multiplexing. The advances and parameter constraints of each multiplexing technology are also discussed.
We have demonstrated the operation of a 12-channel Beyer-style SQUID-based time domain multiplexer. It was manufactured using a fabrication process that is cross-compatible between VTT and IPHT-Jena. The multiplexer consists of twelve 12-SQUID series arrays, each shunted by a Zappe-style interferometer array acting as a flux-controlled superconducting/normal conducting switch. By keeping all switches but one in the superconducting state, it is possible to select one active readout channel at a time. A flux feedback coil common to all SQUID arrays allows realization of a flux-locked loop. We present characteristics of the multiplexer and measurement data from experiments with a 25-pixel X-ray calorimeter array operated at T < 100 mK in a dilution refrigerator.
Abstract A microwave SQUID multiplexer ( μ MUX) with a high multiplexing factor is a promising readout approach for large-scale superconducting transition-edge sensor (TES) bolometer arrays. This paper reports on the characteristics of 16-channel μ MUX prototype chips and a 60-channel readout module developed to read out TES bolometers for the Ali cosmic microwave background polarization telescope (AliCPT). We designed two different coupling structures between the resonator and the radio-frequency superconducting interference device: design A with a mutual inductance ( M T ) of 2.3 pH and design B with an M T of 6.5 pH. For design A, the mean resonator bandwidth ( Δ f BW ) and peak-to-peak frequency shift ( Δ f pp ) are approximately 610 kHz and 290 kHz, respectively. The measured mean open-loop current noise is less than 40 pA / Hz . Preliminary results indicate that crosstalk between adjacent channels is below 1% in our design A μ MUX chip. A measured channel with design B shows a Δ f BW of 586 kHz and a current noise of 33 pA / Hz , similar to the design A channels. In comparison, the Δ f pp of 803 kHz is much larger than the design A channels due to a larger M T . The readout module, consisting of two design A chips and two design B chips, shows 60 resonances, corresponding to a yield of 94%. In the future, we will place 32 design A channels within the same chip dimension to increase the channel density and build a larger readout module suitable for AliCPT TES arrays.
We describe the development of a frequency-domain multiplexer (MUX) to read out arrays of superconducting transition-edge sensors (TES). Fabrication of large-format arrays of these sensors is becoming practical; however, reading out each sensor in the array is a major instrumental challenge. Frequency-domain multiplexing can greatly simplify the instrumentation of large arrays by reducing the number of SQUID's (superconducting quantum interference devices) and wires to the low temperature stages. Each sensor is AC biased at a different frequency, ranging from 380 kHz to 1 MHz. Each sensor signal amplitude-modulates its respective AC bias frequency. An LC filter associated with each sensor suppresses Johnson noise from the other sensors. The signals are combined at a current summing node and measured by a single SQUID. The individual signals from each sensor are then lock-in detected by room temperature electronics. Test chips with fully lithographed LC filters for up to 32 channels have been designed and fabricated. The capacitance and inductance values have been measured and are close to the design goals. We discuss the basic principles of frequency-domain multiplexing, the design and testing of the test chips, and the implementation of a practical system.