Optimal Quantum Metrology of Distant Black Bodies
Optimal Quantum Metrology of Distant Black Bodies
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DOI：
10.22331/q-2017-07-26-21
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发表时间：
2017-01-01
期刊：
影响因子：
6.4
通讯作者：
Kok, Pieter
中科院分区：
文献类型：
--
作者：
Pearce, Mark E.;Campbell, Earl T.;Kok, Pieter
物体温度的测量在从天文学到工程学的许多学科中都很重要，物体空间配置的估计也是如此。我们提出了一个量子最优估计的基础上的黑体辐射在远场接收的远体的温度。我们还展示了如何执行可分离的量子最佳估计的空间配置的一个遥远的对象，即成像。在这样做的时候，我们必须处理不相容的观测量的多参数量子估计，这是一个很难理解的问题。我们比较我们的最佳观测值透镜成像的两个模式的模拟，发现后者是远远不是最佳的，即使是比较的测量是可分离的。为了证明最优的估计，我们表明，他们最小化的成本函数加权的量子Fisher信息，这相当于最大化的平均保真度之间的实际状态和估计。
Measurements of an object's temperature are important in many disciplines, from astronomy to engineering, as are estimates of an object's spatial configuration. We present the quantum optimal estimator for the temperature of a distant body based on the black body radiation received in the far-field. We also show how to perform separable quantum optimal estimates of the spatial configuration of a distant object, i.e. imaging. In doing so we necessarily deal with multi-parameter quantum estimation of incompatible observables, a problem that is poorly understood. We compare our optimal observables to the two mode analogue of lensed imaging and find that the latter is far from optimal, even when compared to measurements which are separable. To prove the optimality of the estimators we show that they minimise the cost function weighted by the quantum Fisher information-this is equivalent to maximising the average fidelity between the actual state and the estimated one.