A new reversible SMG gate and its application for designing two’s complement adder/subtractor with overflow detection logic for quantum computer-based systems

Abstract

Reversible computation plays an important role in the synthesis of circuits having application in quantum computing-, low-power CMOS design-, bioinformatics-, and nanotechnology-based systems. Conventional logical circuits are not reversible. A reversible circuit maps each input vector, into a unique output vector and vice versa. A new 4 × 4 reversible full-adder gate called as SMG gate is suggested in this paper. Three approaches to design reversible two’s complement adder/subtractor with overflow detection logic are also proposed. The first approach is based on Toffoli and Feynman gates, second approach is based on Peres gate, and third approach is based on the new SMG gate. The proposed reversible circuits are evaluated in terms of number of quantum cost.