Group theory based synthesis of binary reversible circuits
Guowu Yang, William N. N. Hung, Marek A. Perkowski
Abstract
Abstract. This paper presents an important result addressing a fundamental question in synthesizing binary reversible logic circuits for quantum computation. We show that any even-reversible-circuit of n (n>3) qubits can be realized using NOT gate and Toffoli gate (‘2’-Controlled-Not gate), where the numbers of Toffoli and NOT gates required in the realization are bounded by (n+ ⌊ n 3 ⌋)(3×22n−3 −2 n+2)and4n(n+ ⌊ n 3 ⌋)2n, respectively. A provable constructive synthesis algorithm is derived. The time complexity of the algorithm is 10 3 n2 · 2 n. Our algorithm is exponentially lower than breadth-first search based synthesis algorithms with respect to space and time complexities. 1