远程协作实现对线性相关对称高维量子态的最大信心辨识

Maximum-confident discrimination among linearly dependent symmetric qudit states implemented by remote parters

利用非局域二维受控-旋转门,Alice远程协助Bob实现对他未知的N个线性相关对称d维量子态的最大信心辨识(N>d).该方案中,一非局域正定算符值测量系列(POVMs)起着关键作用,给出了这些测量算符的最优数学表式.也给出方案的成功概率及完成该方案所花费的纠缠和经典通信资源.值得注意的是,方案中每一非局域POVM只包含两个可用对角矩阵表示的远程测量算子,故仅需(m 1)个二维最大纠缠态就可完成一2m×2m维的非局域POVM.方案在目前的实验条件下是可行的.

Based on nonlocal two-level controlled-rotation gates, the maximum-confident discrimination among N linearly dependent symmetric d-level quantum states implemented by two remote patters could be realized （N〉d）. We present a scheme for such kind of nonlocal maximum-confident quantum state discrimination. In this scheme, the sequential nonlocal positive operator valued measurements （POVMs） lies at the heart. We construct the required optimal POVMs, in which each POVM has only two remote detection operators. We also report on the quantitative relations between the success probability of discrimination, entanglement and classical communication resources required in the implementation. The fact that the two-outcome nonlocal 2mx2m POVM could be realized using only （m-l） two-level maximally entangled pairs is notable. This scheme is feasible for current experimental technology.