Group theory based reversible logic synthesis

With increase in emphasis on low-power design and quantum computation, research in reversible logic synthesis has gained great attention. Various methods of synthesis exist in the literature, like exact synthesis, heuristic approaches, methods based on group theory, and those based on higherlevel representation of functions like Binary Decision Diagram (BDD). In this paper a group theory based synthesis approach for reversible circuits is presented, using both positive-control and negative-control Toffoli gates. The method uses group theoretic rules for factoring permutation cycles for synthesis. The use of both positive and negative control Toffoli gates results in reduction of total number of gates required as compared to previous methods based on group theory. Several worked out examples illustrate the advantage of the proposed approach.