Development of design methodology of superconducting integrated circuit containing pi-shifted Josephson junctions and its applications

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04280
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21060:Electron device and electronic equipment-related
• Research Institution: Yokohama National University
• Principal Investigator: Yamanashi Yuki 横浜国立大学, 大学院工学研究院, 准教授 (70467059)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: パイ遷移ジョセフソン接合 / 単一磁束量子回路

Outline of Final Research Achievements

A superconductor circuit can operate at the frequency of tens GHz with extremely low power consumption. The performance of the superconductor circuit can be improved by introducing pi-shifted Josephson junctions. We developed a design methodology for the superconducting circuits that enables us to design any logic gates with pi-shifted Josephson junctions. We developed a analog circuit simulator for the circuits that contain pi-shifted Josephson junctions. We found that the non-destructive read-out logic gate that contains pi-shifted Josephson junctions can be implemented with less than half of circuit area of the conventional circuit.

Free Research Field

超伝導エレクトロニクス

Academic Significance and Societal Importance of the Research Achievements

本研究により、超伝導回路のさらなる性能向上が可能になった。特に相補出力型の論理ゲートの大幅な小面積化と性能向上は、大規模なディジタル回路に欠かせないデコーダ回路の性能向上につながり、超伝導回路によるランダムアクセスメモリの大幅な小面積化も可能になった。開発したパイ遷移ジョセフソン接合を含む回路の解析ができる回路シミュレータは公開し、国内外の研究者に利用されている。