Quantum metrology with imperfect states and detectors
Quantum metrology with imperfect states and detectors
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DOI：
10.1103/physreva.83.063836
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发表时间：
2011-06-24
影响因子：
2.9
通讯作者：
Walmsley, Ian A.
中科院分区：
文献类型：
--
作者：
Datta, Animesh;Zhang, Lijian;Walmsley, Ian A.
计量的精确度的量子增强可能会受到系统缺陷的影响。可以通过适当地优化输入状态以使其健壮来缓解这些问题，但代价是使状态难以准备。在本文中，我们找出了光学传感器缺陷的主要来源：输入状态准备效率低下、传感器损耗和探测器效率低下。其中第二个受到了极大的关注；我们表明，在光学干涉传感器中，超过标准量子极限的损害是最小的。此外，我们表明，可以在实验室中使用可行的资源制备的光子态允许使用光子数分辨探测器的测量策略，该策略不仅在没有损耗的情况下达到海森堡极限进行相位估计，而且在包括损耗和低效在内的现实场景中提供接近可能的最大精度。特别是，我们给出了三个缺陷来源之间的权衡界限，这将允许真正的量子增强光学计量学
Quantum enhancements of precision in metrology can be compromised by system imperfections. These may be mitigated by appropriate optimization of the input state to render it robust, at the expense of making the state difficult to prepare. In this paper, we identify the major sources of imperfection of an optical sensor: input state preparation inefficiency, sensor losses, and detector inefficiency. The second of these has received much attention; we show that it is the least damaging to surpassing the standard quantum limit in a optical interferometric sensor. Further, we show that photonic states that can be prepared in the laboratory using feasible resources allow a measurement strategy using photon-number-resolving detectors that not only attain the Heisenberg limit for phase estimation in the absence of losses, but also deliver close to the maximum possible precision in realistic scenarios including losses and inefficiencies. In particular, we give bounds for the tradeoff between the three sources of imperfection that will allow true quantum-enhanced optical metrology