Optimization and performance investigation of 1-Toffoli gate quantum full adders for spin-torque-based n-qubit architecture

Abstract

Quantum computing (QC) is suitable for reversible computing due to its inherent parallel processing ability and fast speed. It also helps to address the issue of high-power dissipation in classical computing. Moreover, QC gates are the sequence of elementary operations such as single-qubit rotation and two-qubit entanglement. Elementary quantum operations are required to be reduced for the realization of complex computing. In this paper, optimization of 1-Tofoli gate-based quantum full adders (QFAs) in terms of the number of elementary operations with the help of quantum library {Ry, Rz, √ SWAP} is carried out. Moreover, the performance of two diferent 1-Tofoli QFAs is investigated in terms of execution time, fdelity, and number of electrons required to realize the QFAs. Improvement in fdelity is 0.7% and 0.57% for QFA1 and QFA2, respectively, compared to the fdelity of 2-Tofoli QFA. A 9.97% increase in execution time is mandatory for the QFA2 compared to QFA1. The QFA2 takes 5% more number of electrons in comparison to QFA1.