Depolarizing-channel parameter estimation using noisy initial states
Depolarizing-channel parameter estimation using noisy initial states
复制标题
DOI：
10.1103/physreva.92.032324
复制
发表时间：
2015-09-25
影响因子：
2.9
通讯作者：
Stephens, Jaimie
中科院分区：
文献类型：
--
作者：
Collins, David;Stephens, Jaimie
我们考虑当可能采用的可用初始状态是混合的时，估计与量子比特去极化通道相关联的参数。我们使用量子Fisher信息作为估计的准确性的度量，以比较使用处于产品状态的量子位集合的协议与其中量子位处于相关状态的协议。我们表明，对于某些参数值和初始状态，相关状态协议可以产生更大的准确性，每通道调用比产品状态协议。我们表明，对于某些参数和初始状态，使用两个以上的量子比特和通道调用是有利的。这些结果与已知的使用纯初始状态和对纠缠量子比特的单通道调用的最佳情况形成对比。
We consider estimating the parameter associated with the qubit depolarizing channel when the available initial states that might be employed are mixed. We use quantum Fisher information as a measure of the accuracy of estimation to compare protocols which use collections of qubits in product states to one in which the qubits are in a correlated state. We show that, for certain parameter values and initial states, the correlated-state protocol can yield a greater accuracy per channel invocation than the product-state protocols. We show that, for some parameters and initial states, using more than two qubits and channel invocations is advantageous. These results stand in contrast to the known optimal case that uses pure initial states and a single channel invocation on a pair of entangled qubits.