Superconductor Electronics: Status and Outlook

Abstract

Superconductor electronics combines passive and active superconducting components and sometimes normal resistors into functional circuits and systems that also include room-temperature electronics for amplification, power sources, necessary controls, etc., usually computer operated. Furthermore, complete systems include magnetic and electromagnetic shielding, cryogenic enclosures, and increasingly a cryocooler in self-contained units. Components or devices of low or high critical temperature superconductors include inductances (coils), passive transmission lines, resonators, antennae, filters, as well as active elements: Josephson junctions, Josephson oscillators, and superconducting quantum interference devices. Of multiple demonstrated applications, mostly but not only in science and metrology, currently most successful are voltage standards, astronomy detectors and large telescope cameras, instruments for material characterization, and magnetometers for geomagnetic prospecting. Major current efforts concentrate on energy-efficient high-end computing and quantum computing. The outcomes of these efforts are likely to be known in the course of the following decade.

Synthesis, Characterization, and Magnetoresistive Properties of the Epitaxial Pd0.96Fe0.04/VN/Pd0.92Fe0.08 Superconducting Spin-Valve Heterostructure

“…Underlying physics should allow such elements to overcome the constraints inherent to the complementary metal-oxide-semiconductor (CMOS) electronics. Superconducting logic devices are candidates for supercomputer applications due to their high operating frequency and ultralow energy consumption [ 6 , 7 , 8 , 9 , 10 ]. The conventional Josephson junction [ 11 , 12 ], in which the superconducting current flows due to the phase difference between two superconducting electrodes, is the basic element of superconducting circuits such as single-flux quantum logic (SFQ) [ 13 , 14 ], quantum flux parametron [ 15 , 16 ], reciprocal quantum logic [ 17 , 18 ], and adiabatic superconductor logic [ 19 ].…”

A linear magnetic flux-to-voltage transfer function of a differential DC SQUID

“…Both lowtemperature and high-temperature superconductor (LTS and HTS) technology provide a possibility to fabricate SQUID arrays with the number of Josephson junctions about a million [4,5]. This expands the area of SQUID applications to the one where SQUID-based structures should ideally act as a linear magnetic fluxto-voltage transformers [5][6][7][8][9][10][11]: from electrically small antennas to analog-to-digital convertor circuits and from susceptometers to SQUID-based multiplexers.…”

Millimeter-Wave Four-Wave Mixing via Kinetic Inductance for Quantum Devices

“…Finally we measure degenerate parametric conversion for a 95 GHz device with a forward efficiency up to +16 dB, paving the way for the development of nonlinear quantum devices at millimeter-wave frequencies.For superconducting quantum circuits, the millimeterwave spectrum presents a fascinating frequency regime between microwaves and optics, giving access to a wider range of energy scales, and lower sensitivity to thermal background noise due to higher photon energies. Many advances have been made refining microwave quantum devices [1,2], typically relying on ultra-low temperatures in the millikelvin range to reduce sources of noise and quantum decoherence. Using millimeter-wave photons as building blocks for superconducting quantum devices offers transformative opportunities by allowing quantum experiments to be run at liquid Helium-4 temperatures, allowing higher device power dissipation and enabling large scale direct integration with semiconductor devices [2].…”

“…Many advances have been made refining microwave quantum devices [1,2], typically relying on ultra-low temperatures in the millikelvin range to reduce sources of noise and quantum decoherence. Using millimeter-wave photons as building blocks for superconducting quantum devices offers transformative opportunities by allowing quantum experiments to be run at liquid Helium-4 temperatures, allowing higher device power dissipation and enabling large scale direct integration with semiconductor devices [2]. Millimeter-wave quantum devices could also provide new routes for studying strong-coupling light-matter interactions in this frequency regime [3][4][5][6][7], and present new opportunities for quantum-limited frequency conversion and detection [8,9].Recent interest in next-generation communication devices [10, 11] has led to important advances in sensitive millimeter-wave measurement technology around 100 GHz.…”