Optimal Gaussian metrology for generic multimode interferometric circuit
Optimal Gaussian metrology for generic multimode interferometric circuit
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DOI：
10.1088/1367-2630/ab0604
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发表时间：
2019-03-19
影响因子：
3.3
通讯作者：
Yuasa, Kazuya
中科院分区：
文献类型：
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作者：
Matsubara, Teruo;Facchi, Paolo;Yuasa, Kazuya
当玻色子探针的平均数目固定时，得到了高斯量子计量学中参数估计的最终精度的界。我们确定了最佳的输入探测状态之间的通用（一般混合）高斯状态与固定的平均探测光子数的参数估计包含在一个通用的多模干涉光学电路，即，一个被动的线性电路保持光子的总数。最佳高斯输入态实质上是单模压缩真空，最终的精度是通过对单模的零差测量来实现的。我们还揭示了最佳的估计策略时，我们被赋予L相同的目标电路，并允许应用被动线性控制之间的任意数量的辅助模式的介绍。
Bounds on the ultimate precision attainable in the estimation of a parameter in Gaussian quantum metrology are obtained when the average number of bosonic probes is fixed. We identify the optimal input probe state among generic (mixed in general) Gaussian states with a fixed average number of probe photons for the estimation of a parameter contained in a generic multimode interferometric optical circuit, namely, a passive linear circuit preserving the total number of photons. The optimal Gaussian input state is essentially a single-mode squeezed vacuum, and the ultimate precision is achieved by a homodyne measurement on the single mode. We also reveal the best strategy for the estimation when we are given L identical target circuits and are allowed to apply passive linear controls in between with an arbitrary number of ancilla modes introduced.