Josephson quantum interference computer devices

Zappe, H. H.

doi:10.1109/tmag.1977.1059358

Cited by 99 publications

(13 citation statements)

References 24 publications

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“…Each SQ1 is a four-element series array of dc SQUIDs with a flux-actuated switch. This interferometric-switch architecture was suggested by Zappe [11]. A simpler flux-actuated switch with only two junctions (and thus narrower operating margins) was previously implemented by Beyer and Drung [12].…”

Section: New Tdm Architecturementioning

confidence: 99%

Developments in Time-Division Multiplexing of X-ray Transition-Edge Sensors

et al. 2015

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Time-division multiplexing (TDM) is a mature scheme for the readout of arrays of transition-edge sensors (TESs). TDM is based on superconducting-quantum-interference-device (SQUID) current amplifiers. Multiple spectrometers based on gamma-ray and X-ray microcalorimeters have been operated with TDM readout, each at the scale of 200 sensors per spectrometer, as have several astronomical cameras with thousands of sub-mm or microwave bolometers. Here we present the details of two different versions of our TDM system designed to read out X-ray TESs. The first has been field-deployed in two 160-sensor (8 columns × 20 rows) spectrometers and four 240-sensor (8 columns × 30 rows) spectrometers. It has a three-SQUID-stage architecture, switches rows every 320 ns, and has total readout noise of 0.41 μΦ0/√Hz. The second, which is presently under development, has a two-SQUID-stage architecture, switches rows every 160 ns, and has total readout noise of 0.19 μΦ0/√Hz. Both quoted noise values are non-multiplexed and referred to the first-stage SQUID. In a demonstration of this new architecture, a multiplexed 1-column × 32-row array of NIST TESs achieved average energy resolution of 2.55±0.01 eV at 6 keV.

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Section: New Tdm Architecturementioning

confidence: 99%

Developments in Time-Division Multiplexing of X-ray Transition-Edge Sensors

et al. 2015

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“…The polarity modulator contains superconducting switches 10 In I-CDM, the TES detectors are dc biased. The average voltage bias level V on each pixel is set by applying a repeating linear current ramp I bias (t) to the coupled inductor in Fig.…”

Section: Superconducting Polarity Modulation Switchesmentioning

confidence: 99%

“…The switches used in I-CDM consist of four Josephson junctions rather than two (Fig. 1b), which allows both larger operating margins and higher current-carrying capacity than two-junction switches10 . The new switches work well, have high yield, and have wide operating margins.III.…”

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confidence: 99%

Advanced Code-Division Multiplexers for Superconducting Detector Arrays

et al. 2012

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Multiplexers based on the modulation of superconducting quantum interference devices are now regularly used in multi-kilopixel arrays of superconducting detectors for astrophysics, cosmology, and materials analysis. Over the next decade, much larger arrays will be needed. These larger arrays require new modulation techniques and compact multiplexer elements that fit within each pixel. We present a new in-focal-plane code-division multiplexer that provides multiplexing elements with the required scalability. This codedivision multiplexer uses compact lithographic modulation elements that simultaneously multiplex both signal outputs and superconducting transition-edge sensor (TES) detector bias voltages. It eliminates the shunt resistor used to voltage bias TES detectors, greatly reduces power dissipation, allows different dc bias voltages for each TES, and makes all elements sufficiently compact to fit inside the detector pixel area.These in-focal-plane code-division multiplexers can be combined with multi-gigahertz readout based on superconducting microresonators to scale to even larger arrays.

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“…The associated power dissipation may prohibit some large scale implementations. Tunnel-junction-based switches [7][8][9] can operate at sub-Kelvin temperatures, but either have high currentcapacity with high leakage current or low current-capacity with low leakage current. In this letter, we demonstrate a high current-capacity ($1 mA) cryotron switch that requires a low actuation current and is suitable for use at sub-Kelvin temperatures.…”

mentioning

confidence: 99%

A thin-film cryotron suitable for use as an ultra-low-temperature switch

Lowell

Mates

Doriese

et al. 2016

Applied Physics Letters

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Low-temperature superconducting circuits have become important for many scientific applications. However, there are presently no high current-capacity switches (∼1 mA) with low power dissipation for sub-Kelvin operation. One candidate for a sub-Kelvin switch is the cryotron, a device in which the superconductivity of a wire is suppressed with a magnetic field. Here, we demonstrate a cryotron switch suitable for sub-Kelvin temperatures. In the closed state, the maximum device current is about 900 μA. The device is switched to its open state with 2 mA of control current and has a leakage of approximately 500 nA. The transition between the closed and open states of the device is faster than 200 ns, where the measurement is limited by the speed of our measurement apparatus. We also discuss low-temperature applications for our cryotron such as a single-pole, double-throw switch.

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Josephson quantum interference computer devices

Cited by 99 publications

References 24 publications

Developments in Time-Division Multiplexing of X-ray Transition-Edge Sensors

Developments in Time-Division Multiplexing of X-ray Transition-Edge Sensors

Advanced Code-Division Multiplexers for Superconducting Detector Arrays

A thin-film cryotron suitable for use as an ultra-low-temperature switch

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