Recent Progress on Reversible Quantum-Flux-Parametron for Superconductor Reversible Computing


IEICE TRANSACTIONS on Electronics   Vol.E101-C   No.5   pp.352-358
Publication Date: 2018/05/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E101.C.352
Type of Manuscript: INVITED PAPER (Special Section on Innovative Superconducting Devices Based on New Physical Phenomena)
reversible computing,  adiabatic logic,  QFP,  

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We have been investigating reversible quantum-flux-parametron (RQFP), which is a reversible logic gate using adiabatic quantum-flux-parametron (AQFP), toward realizing superconductor reversible computing. In this paper, we review the recent progress of RQFP. Followed by a brief explanation on AQFP, we first review the difference between irreversible logic gates and RQFP in light of time evolution and energy dissipation, based on our previous studies. Numerical calculation results reveal that the logic state of RQFP can be changed quasi-statically and adiabatically, or thermodynamically reversibly, and that the energy dissipation required for RQFP to perform a logic operation can be arbitrarily reduced. Lastly, we show recent experimental results of an RQFP cell, which was newly designed for the latest cell library. We observed the wide operation margins of more than 4.7dB with respect to excitation currents.