High-speed superconductive circuitry: An overview

Stephen R. Whiteley, Eric Hanson, G.B.G. Hohenwater +2 more

HYPRES, Inc. has introduced a Sampling Oscilloscope/Time Domain Reflectometer (TDR) based on Josephson junction technology to the commercial marketplace. The unit offers measurement performance commensurate with the inherent high speed of the Josephson elements, e.g., risetimes on the order of 8 ps. The Josephson circuitry is contained on a single 1.1 × 1.6 fused silica substrate and housed in an interchangeable measurement module. Only the portion of the chip which contains the superconducting circuitry is cooled with a coplanar transmission line providing the wide bandwidth interface between the room temperature and cryogenic environments less than 1cm apart.

Gleb Krylov, Eby G. Friedman

Mark W. Coffey

Two classes of superconducting devices have been proposed as quantum bits (qubits) for realizing quantum logic operations. The flux qubits based on a superconducting quantum interference device (SQUID) appear to be particularly promising owing to the macroscopic nature of the qubit and potential integration with high-speed control circuitry in the form of rapid single-flux quantum electronics. Recent progress is discussed and near-term challenges mentioned. The radio frequency SQUID-based qubit offers a prospect for a reliably manufacturable scalable approach.

Gleb Krylov, Tahereh Jabbari, Eby G. Friedman

Stephen R. Whiteley, Gert K. G. Hohenwarter, S. M. Faris

Using a novel chip architecture and cooling method, a superconducting Josephson Junction time domain reflectometer subsystem has been developed which provides wide bandwidth access to the room temperature environment. Presented is an overview of the subsystem, with emphasis on the cryogenic circuitry employed. Results and performance limitations are described.

C. R. Vail, John L. Artley