Optimal estimation of joint parameters in phase space
Optimal estimation of joint parameters in phase space
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DOI：
10.1103/physreva.87.012107
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发表时间：
2013-01-09
影响因子：
2.9
通讯作者：
Kim, M. S.
中科院分区：
文献类型：
--
作者：
Genoni, M. G.;Paris, M. G. A.;Kim, M. S.
我们讨论了相空间中位移运算的两个定义参数的联合估计问题。在一个基于高斯探测场和两个零差探测器的测量方案中，当探测场处于纠缠状态时，这两个共轭参数都可以测量到低于标准量子极限。我们推导出了信息量最大的Cramer-Rao界，为估计提供了理论基准，并观察到我们的方案对于描述探测场的宽参数范围几乎是最优的。我们讨论了纠缠的作用以及我们的测量策略与广义测不准关系之间的关系。DOI：10.1103/PhysRevA.87.012107
We address the joint estimation of the two defining parameters of a displacement operation in phase space. In a measurement scheme based on a Gaussian probe field and two homodyne detectors, it is shown that both conjugated parameters can be measured below the standard quantum limit when the probe field is entangled. We derive the most informative Cramer- Rao bound, providing the theoretical benchmark on the estimation, and observe that our scheme is nearly optimal for a wide parameter range characterizing the probe field. We discuss the role of the entanglement as well as the relation between our measurement strategy and the generalized uncertainty relations. DOI: 10.1103/PhysRevA.87.012107