Estimation of a generalized amplitude-damping channel
Estimation of a generalized amplitude-damping channel
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DOI：
10.1103/physreva.70.012317
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发表时间：
2004-07-01
影响因子：
2.9
通讯作者：
Fujiwara, A
中科院分区：
文献类型：
--
作者：
Fujiwara, A
研究了利用扩展的idxGamma(Eta)((P))来估计广义幅度衰减信道Gamma(Eta)((P))的最优策略问题。我们首先基于对称的对数导数计算输出态的量子Fisher信息，并指定所有使量子Fisher信息最大化的纯态输入。接下来，我们研究了输出状态流形的del(E)自并行性，并刻画了有效估计量存在的条件。这些结果的比较表明，尽管对于所有的p和eta都不存在一致最优输入，但在非渐近设置下，最大纠缠输入是允许的。
The problem of finding the optimal strategy for estimating a generalized amplitude damping channel Gamma(eta)((p)) by means of the extension idxGamma(eta)((p)) is addressed. We first evaluate the quantum Fisher information of output states based on the symmetric logarithmic derivative and specify all pure-state inputs that maximize the quantum Fisher information. We next investigate the del(e) autoparallelity of output state manifolds and characterize the condition for the existence of an efficient estimator. A comparison of these results concludes that, while there is no uniformly optimal input for all p and eta, a maximally entangled input is an admissible one under a nonasymptotic setting.