Extremely energy efficient digital logic based on adiabatic quantum flux parametron
For realizing future exascale high-performance computers, extremely energy-efficient logic is highly demanded. The aim of this study is the realization of extraordinarily energy-efficient logic circuits operating in the thermodynamic energy limit using superconducting logic circuits. Our approach utilizes the adiabatic operation of adiabatic quantum-flux-parametron (AQFP) by changing its phase difference adiabatically or very slowly. The relationship between the bit energy and the clock period is the target figure of merit. The bit energy of the AQFP circuits is six orders of magnitude smaller than that of the state-of-the-art CMOS circuits. We study the fundamental technology to realize energy-efficient integrated circuits based on the AQFP circuits. The final target is to demonstrate the high-speed operation of an AQFP processor at 5 GHz with a total power consumption of less than 1 µW.