A Faster Half Subtractor Circuit Using Reversible Quantum Gates

Abstract

Quantum computers base their operations on optimized circuit designs. These quantum circuits, unlike classic circuits, follow the set of rules determined by quantum mechanics. Currently, one of the main problems to solve in Quantum Computation is Shor's algorithm, which consists in factoring large numbers. It is based on arithmetic operations, therefore to optimize such operations is hence relevant. In this work, a novel half subtractor circuit is presented; it is referred to as F GE * and it has demonstrated to be a 25% faster than the state-of-the-arts reversible circuits. It is based on reversible quantum gates and it does not have any garbage output. Moreover, a robust metric is considered for comparing, in terms of resources and speed, the proposed circuit with other circuits in the literature.