A Universal Quantum Phase Slip Logic Gate for Implementing Basic Boolean Functions

Abstract

Quantum phase slip (QPS) junction can act as a superconductor switch when a voltage pulse larger than its critical voltage is applied to it. As a result, a current pulse with an area equal to 2e (or multiples of 2e) flows across the junction, and the junction switches from zero to one in the charge-base logic. For having a proper operation simulation of the QPS junction, it should be overdamped, and the damping factor should be less than one. Physical parameters of the QPS junction, namely, the normal resistance, the kinetic inductance, and the critical voltage, can affect the overdamping condition and switching behavior of the junction, as well as the damping factor. The basic block for designing the QPS logic gates is the charge island. By different and proper connections of the charge islands, basic QPS and, or, and xor logic gates are designed. Generally, each of these gates has its own circuit and junction parameters for proper operation. In this manuscript, a universal QPS logic gate is proposed that can perform basic and, or, and xor Boolean functions by proper selection of parameters for QPS junctions in the case of each Boolean function. This universal QPS logic gate can simplify the design the complicated QPS logic circuits, since only the parameters of each junction have to be properly selected for achieving the desired Boolean function, and the gate circuit topology remains unchanged.