高维辅助的普适量子线路优化  

Optimizing quantum circuits using higher-dimensional Hilbert spaces

作　　者：刘凯[1] 李文东[1] 张闻钊[1] 史鹏[1] 任春年[1] 顾永建[1] 

机构地区：[1]中国海洋大学物理系,青岛266100

出　　处：《物理学报》2012年第12期28-34,共7页Acta Physica Sinica

摘　　要：受到Lanyon等(Lanyon B P et al 2008 Nature Physics 5 134)利用高维Hilbert空间成功简化Toffoli门的启发,本文将辅助维度应用到普适量子线路中,结合Cosine-Sine Decomposition(CSD),Quantum Shannon Decomposition(QSD)等矩阵分解方法,优化了两比特和三比特普适幺正量子线路,给出了计算n比特普适量子线路复杂度的公式,并利用线性光学和腔QED系统设计了实验方案.结果表明,两比特和三比特量子线路的复杂度已分别接近和优于目前最优结果,且随着比特数的增加,本方案的优势愈加明显.Inspired by Lanyon （B. P. Lanyon et al. 2008 Nature Physics 5 134） successfully simplifying the three-qubit Toffoli gate, we present a novel scheme that optimizes universal quantum logic circuits using assisted higher-dimensional Hilbert space. We construct a more efficient two-qubit circuit and a more effective three-qubit universal quantum circuit by using assisted dimension, CosineSine Decomposition （CSD） and Quantum Shannon Decomposition （QSD）. Meanwhile, we present the formula for the complexity of arbitrary n-qubit universal quantum gate. We propose the physical implementation of this scheme by linear optical circuits and cavity- QED. The results show that the two-qubit and three-qubit universal quantum circuits are respectively close and superior to the current optimal scheme in complexity. And with the increase of the number of qubits, the advantage of our scheme will become increasingly prominent.

关 键 词：辅助维度 量子线路 复杂度 

分 类 号：O431.2[机械工程—光学工程]