无相互作用费米量子信道直积态容量研究  

Tensor Product State Capacity of Non-interacting Fermion Quantum Channel

作　　者：彭永刚[1] 巩龙 

机构地区：[1]南京邮电大学理学院应用物理系,南京210003

出　　处：《光子学报》2011年第9期1392-1396,共5页Acta Photonica Sinica

基　　金：国家自然科学基金(No.10904074)资助

摘　　要：用费米线性光学方法,提出无相互作用费米量子信道物理模型.用平稳量子高斯态协方差矩阵性质及Majorization不等式理论,推导出在平稳高斯输入态下费米量子信道最小输出熵的表达式.利用在n模费米系统添加一个额外模的方法,得到平稳高斯态和高斯态输出熵的关系;利用此关系式,借助在高斯输入态下费米信道最小输出熵值是可达的猜测,推导出无相互作用费米信道直积态容量的表达式.最后,用最小输出熵的迭代算法验证已推出的费米信道最小输出熵表达式正确性,数值计算结果表明:对于带噪声的无相互作用费米量子信道,已推出最小输出熵与数值计算结果的吻合度可以达到10e-9.The physical model of non-interacting fermion quantum channel is proposed by fermionic linear optics. Based on covariance matrix property of even Gaussian state and majorization theory, a formula of fermion quantum channel minimum output entropy for even Gaussian input state is deduced. A output entropy correspondence between Gaussian state and even Gaussian state is established by adding one extra fermionie mode to n-qubit fermion system. A formula of tensor product state capacity for non-interacting fermion channel is deduced according this output entropy correspondence and under assumption that minimum output entropy is achieved on a Gaussian input state. For fermionic channel correct of proposed minimum output entropy formula is confirmed by the iterative minimization algorithm of output entropy. The numerical results is that for non-interacting fermion noisy quantum channel the proposed formula agrees with the numerical results with a precision about 10e-9.

关 键 词：量子信道 无相互作用费米系统 直积态容量 量子高斯态 最小输出熵 

分 类 号：O431.2[机械工程—光学工程]