2013/01/15 by Nengkun Yu, Runyao Duan, Mingsheng Ying · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.88.010304
published as Phys. Rev. A 88, 010304(R) (2013) · 5 Pages, comments welcome
arxiv created 2013/01/15 · arxiv updated 2013/09/24
In this paper, we settle the long-standing open problem of the minimum cost of two-qubit gates for simulating a Toffoli gate. More precisely, we show that five two-qubit gates are necessary. Before our work, it is known that five gates are sufficient and only numerical evidences have been gathered, indicating that the five-gate implementation is necessary. The idea introduced here can also be used to solve the problem of optimal simulation of three-qubit control phase introduced by Deutsch in 1989.