RSFQ Technology: Circuits and Systems

Abstract

Rapid Single-Flux-Quantum (RSFQ) logic is a superconductor IC technology that, with only a modest number of researchers worldwide, has produced some of the world's highest performance digital and mixed-signal circuits. This achievement is due, in part, to a constellation of characteristics that manifest themselves at the circuit level -namely, highspeed digital logic at low-power, ideal interconnects, quantum accuracy, scalability, and simplicity of fabrication. A necessary key to translating these advantages to the systemlevel involves understanding the I/O, synchronization, and packaging issues associated with a cryogenic technology. The objective of this paper is to review the status of current RSFQ circuit-level infrastructure components and their potential impact on system-level applications.

Quantum computing with superconductors

“…4) Ultrasensitive magnetometers [35], [36] and electrometers [37] can be fabricated out of superconductors to read out the state of the computer. 5) A classical control electronics family (single-flux quantum (SFQ) electronics) [38], [39] exists that can be integrated with the superconductive qubits for classical control operations [40]- [42]. To examine in more detail the requirements for a technology, it is helpful to have a sample architecture in mind.…”

“…The most promising classical control electronics family (SFQ electronics) [38], [39] has been used extensively for implementation of analog, digital, and mixed-signal integrated circuits. Several proposals exist for use of these circuits to control quantum bit operations [40]- [42].…”

Digital SQUIDs: New definitions and results

“…In the framework of the approach digital data are stored and transferred by means of Single Flux Quanta (SFQ). There are a few reviews discussing this so-called Rapid SFQ (RSFQ) logic [3]- [5].…”

Global interconnects in VLSI complexity single flux quantum systems

“…An important characteristic of SFQ circuits is absolute zero DC resistance interconnects [6]. SFQ circuits utilize two distinct types of interconnect -active Josephson transmission lines (JTL) and passive transmission lines (PTL), composed of a microstrip or stripline with a matched driver and receiver [7][8][9].…”