Nobuyuki Yoshikawa

The reversible quantum-flux-parametron (RQFP) is a reversible logic gate based on an energy-efficient superconductor logic family, namely, the adiabatic quantum-flux-parametron logic. The RQFP can perform logic operations in a thermodynamically reversible manner (i.e., without energy dissipation) in the quasi-static limit due to its logical and physical reversibility. Hence, it can be used for investigating the fundamental relations between information and thermodynamics from a circuit perspective. In the present study, we propose a reversible flip-flop (RFF) comprising an RQFP and investigate the minimum energy dissipation required for general information processing through numerical simulation using an RFF-based circuit. This circuit includes fundamental information processing (combinational logic, sequential logic, and data erasure) and can, thus, be used as a physical model for such an investigation. The numerical simulation of this circuit shows that both combinational and sequential logic operations can be conducted without energy dissipation in the quasi-static limit and that the amount of erased data determines the minimum energy dissipation. These results indicate that general information processing can be conducted in a thermodynamically reversible manner by using RQFP circuits as long as all data, including garbage outputs, are conserved.