Controlled and Uncontrolled SWAP Gates in Reversible Logic Synthesis

摘要

This paper presents a quantum-level realization and synthesis approach using SWAP and Fredkin (SF) gates. Our quantum realization of negative-controlled Fredkin gate requires five 2-qubit elementary quantum gates, the same as that required for realizing a positive-controlled Fredkin gate. We also propose and evaluate the performance of a synthesis approach using SF gates for realizing conservative reversible functions. Our result shows that circuit realization for conservative function using SF gates is more efficient than Toffoli gates. We achieve up to 87% improvement in gate count and quantum cost for (4 × 4) conservative reversible functions.