41 research outputs found

    Spin Detection, Amplification, and Microwave Squeezing with Kinetic Inductance Parametric Amplifiers

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    Superconducting parametric amplifiers operating at microwave frequencies have become an essential component in circuit quantum electrodynamics experiments. They are used to amplify signals at the single-photon level, while adding only the minimum amount of noise required by quantum mechanics. To achieve gain, energy is transferred from a pump to the signal through a non-linear interaction. A common strategy to enhance this process is to place the non-linearity inside a high quality factor resonator, but so far, quantum limited amplifiers of this type have only been demonstrated from designs that utilize Josephson junctions. Here we demonstrate the Kinetic Inductance Parametric Amplifier (KIPA), a three-wave mixing resonant parametric amplifier that exploits the kinetic inductance intrinsic to thin films of disordered superconductors. We then utilize the KIPA for measurements of 209Bi spin ensembles in Si. First, we show that a KIPA can serve simultaneously as a high quality factor resonator for pulsed electron spin resonance measurements and as a low-noise parametric amplifier. Using this dual-functionality, we enhance the signal to noise ratio of our measurements by more than a factor of seven and ultimately achieve a measurement sensitivity of 2.4 x 10^3 spins. Then we show that pushed to the high-gain limit, KIPAs can serve as a `click'-detector for microwave wave packets by utilizing a hysteretic transition to a self-oscillating state. We calibrate the detector's sensitivity to be 3.7 zJ and then apply it to measurements of electron spin resonance. Finally, we demonstrate the suitability of the KIPA for generating squeezed vacuum states. Using a cryogenic noise source, we first confirm the KIPAs in our experiment to be quantum limited amplifiers. Then, using two KIPAs arranged in series, we make direct measurements of vacuum noise squeezing, where we generate itinerant squeezed states with minimum uncertainty more than 7 dB below the standard quantum limit. High quality factor resonators have also recently been used to achieve strong coupling between the spins of single electrons in gate-defined quantum dots and microwave photons. We present our efforts to achieve the equivalent goal for the 31P flip-flop qubit. In doing so, we confirm previous predictions that the superconducting material MoRe would produce magnetic field-resilient resonators and demonstrate that it has kinetic inductance equivalent to the popular material NbTiN

    Low Power Memory/Memristor Devices and Systems

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    This reprint focusses on achieving low-power computation using memristive devices. The topic was designed as a convenient reference point: it contains a mix of techniques starting from the fundamental manufacturing of memristive devices all the way to applications such as physically unclonable functions, and also covers perspectives on, e.g., in-memory computing, which is inextricably linked with emerging memory devices such as memristors. Finally, the reprint contains a few articles representing how other communities (from typical CMOS design to photonics) are fighting on their own fronts in the quest towards low-power computation, as a comparison with the memristor literature. We hope that readers will enjoy discovering the articles within

    Extremely Large Area (88 mm X 88 mm) Superconducting Integrated Circuit (ELASIC)

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    Superconducting integrated circuit (SIC) is a promising "beyond-CMOS" device technology enables speed-of-light, nearly lossless communications to advance cryogenic (4 K or lower) computing. However, the lack of large-area superconducting IC has hindered the development of scalable practical systems. Herein, we describe a novel approach to interconnect 16 high-resolution deep UV (DUV EX4, 248 nm lithography) full reticle circuits to fabricate an extremely large (88mm X 88 mm) area superconducting integrated circuit (ELASIC). The fabrication process starts by interconnecting four high-resolution DUV EX4 (22 mm X 22 mm) full reticles using a single large-field (44 mm X 44 mm) I-line (365 nm lithography) reticle, followed by I-line reticle stitching at the boundaries of 44 mm X 44 mm fields to fabricate the complete ELASIC field (88 mm X 88 mm). The ELASIC demonstrated a 2X-12X reduction in circuit features and maintained high-stitched line superconducting critical currents. We examined quantum flux parametron (QFP) circuits to demonstrate the viability of common active components used for data buffering and transmission. Considering that no stitching requirement for high-resolution EX4 DUV reticles is employed, the present fabrication process has the potential to advance the scaling of superconducting quantum devices

    Revealing Josephson vortex dynamics in proximity junctions below critical current

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    Made of a thin non-superconducting metal (N) sandwiched by two superconductors (S), SNS Josephson junctions enable novel quantum functionalities by mixing up the intrinsic electronic properties of N with the superconducting correlations induced from S by proximity. Electronic properties of these devices are governed by Andreev quasiparticles [1] which are absent in conventional SIS junctions whose insulating barrier (I) between the two S electrodes owns no electronic states. Here we focus on the Josephson vortex (JV) motion inside Nb-Cu-Nb proximity junctions subject to electric currents and magnetic fields. The results of local (Magnetic Force Microscopy) and global (transport) experiments provided simultaneously are compared with our numerical model, revealing the existence of several distinct dynamic regimes of the JV motion. One of them, identified as a fast hysteretic entry/escape below the critical value of Josephson current, is analyzed and suggested for low-dissipative logic and memory elements.Comment: 11 pages, 3 figures, 1 table, 43 reference

    Understanding Quantum Technologies 2022

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    Understanding Quantum Technologies 2022 is a creative-commons ebook that provides a unique 360 degrees overview of quantum technologies from science and technology to geopolitical and societal issues. It covers quantum physics history, quantum physics 101, gate-based quantum computing, quantum computing engineering (including quantum error corrections and quantum computing energetics), quantum computing hardware (all qubit types, including quantum annealing and quantum simulation paradigms, history, science, research, implementation and vendors), quantum enabling technologies (cryogenics, control electronics, photonics, components fabs, raw materials), quantum computing algorithms, software development tools and use cases, unconventional computing (potential alternatives to quantum and classical computing), quantum telecommunications and cryptography, quantum sensing, quantum technologies around the world, quantum technologies societal impact and even quantum fake sciences. The main audience are computer science engineers, developers and IT specialists as well as quantum scientists and students who want to acquire a global view of how quantum technologies work, and particularly quantum computing. This version is an extensive update to the 2021 edition published in October 2021.Comment: 1132 pages, 920 figures, Letter forma

    DC flux parametron : a new approach to Josephson junction logic

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    ix, 200 p. : ill. ; 24 cm

    Gigahertz Sub-Landauer Momentum Computing

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    We introduce a fast and highly-efficient physically-realizable bit swap. Employing readily available and scalable Josephson junction microtechnology, the design implements the recently introduced paradigm of momentum computing. Its nanosecond speeds and sub-Landauer thermodynamic efficiency arise from dynamically storing memory in momentum degrees of freedom. As such, during the swap, the microstate distribution is never near equilibrium and the memory-state dynamics fall far outside of stochastic thermodynamics that assumes detailed-balanced Markovian dynamics. The device implements a bit-swap operation -- a fundamental operation necessary to build reversible universal computing. Extensive, physically-calibrated simulations demonstrate that device performance is robust and that momentum computing can support thermodynamically-efficient, high-speed, large-scale general-purpose computing that circumvents Landauer's bound.Comment: 18 pages, 11 figures, 5 appendices; http://csc.ucdavis.edu/~cmg/compmech/pubs/gslmc.ht

    A Cost and Power Feasibility Analysis of Quantum Annealing for NextG Cellular Wireless Networks

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    In order to meet mobile cellular users' ever-increasing data demands, today's 4 G and 5 G wireless networks are designed mainly with the goal of maximizing spectral efficiency. While they have made progress in this regard, controlling the carbon footprint and operational costs of such networks remains a long-standing problem among network designers. This paper takes a long view on this problem, envisioning a NextG scenario where the network leverages quantum annealing for cellular baseband processing. We gather and synthesize insights on power consumption, computational throughput and latency, spectral efficiency, operational cost, and feasibility timelines surrounding quantum annealing technology. Armed with these data, we project the quantitative performance targets future quantum annealing hardware must meet in order to provide a computational and power advantage over CMOS hardware, while matching its whole-network spectral efficiency. Our quantitative analysis predicts that with 82.32 μ s problem latency and 2.68 M qubits, quantum annealing will achieve a spectral efficiency equal to CMOS while reducing power consumption by 41 kW (45% lower) in a Large MIMO base station with 400 MHz bandwidth and 64 antennas, and a 160 kW power reduction (55% lower) using 8.04 M qubits in a CRAN setting with three Large MIMO base stations

    DC flux parametron : a new approach to Josephson junction logic

    No full text
    ix, 200 p. : ill. ; 24 cm
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