Self-consistent state and measurement tomography with fewer measurements
Self-consistent state and measurement tomography with fewer measurements
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DOI：
10.1103/physreva.104.012416
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发表时间：
2021-07
影响因子：
2.9
通讯作者：
A. Stephens;J. M. Cutshall;T. McPhee;M. Beck
中科院分区：
文献类型：
--
作者：
A. Stephens;J. M. Cutshall;T. McPhee;M. Beck
我们描述了一种技术，用于自洽地表征单量子比特系统的量子态和描述系统测量的正算子值测量（POVM）。该方法只需十次测量即可工作。我们假设在量子态上进行的一系列幺正变换是完全已知的，同时对态的密度算符和POVM做最小的假设。该技术返回密度算子和POVM的最大可能估计。为了实验证明该方法，我们进行了超过300个状态测量对的重建，并将它们与预期的密度算子和POVM进行比较。我们发现，95%的重建POVM具有0.98或更大的结晶度，92%的密度算子具有0.98或更大的结晶度。
We describe a technique for self consistently characterizing both the quantum state of a singlequbit system, and the positive-operator-valued measure (POVM) that describes measurements on the system. The method works with only ten measurements. We assume that a series of unitary transformations performed on the quantum state are fully known, while making minimal assumptions about both the density operator of the state and the POVM. The technique returns maximum-likely estimates of both the density operator and the POVM. To experimentally demonstrate the method, we perform reconstructions of over 300 state-measurement pairs and compare them to their expected density operators and POVMs. We find that 95% of the reconstructed POVMs have fidelities of 0.98 or greater, and 92% of the density operators have fidelities that are 0.98 or greater.