Josephson semiconductor interface circuit

K. Nakahara, Hideyuki Nagaishi, Hiroaki HASEGAWA +3 more

An optical input/output interface system for a Josephson junction integrated circuit is fabricated and tested. The system consists of a superconducting optical detector, a dc powered Josephson circuit, a dc powered Josephson high voltage circuit, a liquid-He-cooled semiconductor amplifier, and a liquid-He-cooled semiconductor laser. Features of the system are use of an ultrathin NbN film for the optical detector and adoption of the dc powered Josephson circuits for logic operation circuits. Correct optical output signal is detected by a liquid-He-cooled semiconductor photodiode. The optical input/output interface has the advantage of low heat penetration and low crosstalk compared to the interface using conventional coaxial lines. Moreover, dc powered Josephson circuits have an advantage of low crosstalk from power supply lines compared to conventional Josephson circuits, which are driven by ac supply current.>

W. Jutzi

Huang-Tian Chan

Akira Shoji

In this paper, the author describes studies on electronic devices and circuits utilizing both of superconductors and semniconductors. First, a design of an interface circuit composed of Josephson junctions and MOSFETs is described. The Josephson-MOS interface circuit will be used for realizing high-speed data communication between a Josephson digital circuit and a semiconductor one. Second, fabrication and characterization of MOSFETs with superconductive NbN gate electrodes are described. The use of superconductive gates makes it easy to hybridize MOSFETs with Josephson junctions. Finally, studies of Josephson-CMOS hybrid memory circuits are introduced.

Uttam Ghoshal, T. Van Duzer, Harry Kroger

The authors describe the development of circuit models, applications of superconducting field effect transistors (SFETs), and higher-voltage Josephson junction (HVJJ) circuits which are important for the feasibility of several novel hybrid superconducting-semiconducting circuits. They also discuss the delay optimization involved in designing and embedding interface circuits in a hybrid superconductor-semiconductor technology. It is noted that, with the advances made in semiconductor technologies, interfaces between the two technologies are practical now and the advantages of hybrid circuits in various applications should be realizable in practice. In the case of interfacing typical Nb-based Josephson junction circuits to 0.5 mu m CMOS technologies, it was estimated that the minimum delay through the interface is approximately 110 ps and the optimum number of junctions in each branch of the HVJJ circuits is 10.>

Oleg A. Mukhanov, Nobuyuki Yoshikawa, Ivan P. Nevirkovets +1 more