Extremal equation for optimal completely positive maps -: art. no. 062310

被引：38

作者：

Fiurásek, J ^{[1
]}

机构：

[1] Palacky Univ, Dept Opt, Olomouc 77200, Czech Republic

来源：

PHYSICAL REVIEW A | 2001年 / 64卷 / 06期

关键词：

D O I：

10.1103/PhysRevA.64.062310

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

We derive an extremal equation for an optimal completely positive map, which most closely approximates a given transformation between pure quantum states. Moreover, we also obtain an upper bound on the maximal mean fidelity that can be attained by the optimal approximate transformation. The developed formalism is applied to a universal-NOT gate, quantum cloning machines, quantum entanglers, and a qubit theta shifter.

引用

页数：7

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