Ancilla-Assisted Calibration of a Measuring Apparatus
Ancilla-Assisted Calibration of a Measuring Apparatus
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DOI：
10.1103/physrevlett.108.253601
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发表时间：
2012-06-19
影响因子：
8.6
通讯作者：
Polyakov, S. V.
中科院分区：
文献类型：
--
作者：
Brida, G.;Ciavarella, L.;Polyakov, S. V.
量子测量可以用一组矩阵来描述，每个矩阵代表一个可能的结果，它代表传感器的正算子值测量（POVM）。对于任意传感器，需要有效的POVM提取协议。我们提出了第一个实验POVM重建，它明确利用了量子资源，即与辅助状态的非经典关联。利用参数下转换产生的双光束的强量子关联，重构了光子数分辨探测器的POVM。我们的重建方法比使用经典输入状态的POVM重建方法具有更强的统计鲁棒性。
A quantum measurement can be described by a set of matrices, one for each possible outcome, which represents the positive operator-valued measure (POVM) of the sensor. Efficient protocols of POVM extraction for arbitrary sensors are required. We present the first experimental POVM reconstruction that takes explicit advantage of a quantum resource, i.e., nonclassical correlations with an ancillary state. A POVM of a photon-number-resolving detector is reconstructed by using strong quantum correlations of twin beams generated by parametric down-conversion. Our reconstruction method is more statistically robust than POVM reconstruction methods that use classical input states.