A Novel Approach Towards Optimized Synthesis of Four Variable Reversible Function Using Toffoli-Fredkin Based Mixed Templates

Abstract

In the arena of reversible computation, several algorithms for synthesizing reversible circuit have contributed a major part. Good number of algorithms for optimized reversible circuit design is available in literature. In our previous work we proposed a synthesis algorithm for four variable reversible circuits using Toffoli Gates only, which outperforms already proposed synthesis algorithm in terms of both gate count and as well as quantum cost. The current work proposes another synthesis algorithm for four bit reversible functions using pre-designed templates combining both Toffoli and Fredkin gates. Template design considers optimal Control Sets for combined Toffoli and Fredkin gates in terms of gate count. These combined Toffoli-Fredkin templates further improve upon the gate count. Comparative study of previously proposed synthesized algorithms having Toffoli gates alone with mixed Toffoli-Fredkin version clearly exhibits the gate count improvements.