Non-Markovian effect on quantum optical metrology under a dissipative environment
Non-Markovian effect on quantum optical metrology under a dissipative environment
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耗散环境下量子光学计量的非马尔可夫效应
DOI：
10.1103/physreva.101.022115
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发表时间：
2020-02-26
影响因子：
2.9
通讯作者：
Xiao, Meng
中科院分区：
文献类型：
--
作者：
Bai, Kai;Luo, Hong-Gang;Xiao, Meng
与经典计量相比，量子计量利用量子效应实现更高精度的物理量测量。然而，普遍存在的退相干阻碍了它的应用。最近，非马尔可夫效应被证明在局部耗散环境下执行量子光学计量是有效的\引用{PhysRevLett.123.040402}。然而，其机制仍然相当模糊。在这里，我们揭示了为什么形成束缚态可以通过纠缠相干态的量子费希尔信息来保护量子性免受耗散环境的影响。推导了长编码时间条件下量子Fisher信息的精确解析表达式，揭示了当平均光子数较小时，动态精度可以轻松地渐近达到理想情况下所承诺的精度。同时，随着平均光子数的增加，标度呈现出从弱海森堡极限到亚经典极限的转变。我们的工作提供了一种利用非马尔可夫效应在存在噪声的情况下实现超灵敏测量的方法。
Quantum metrology utilizes quantum effects to reach higher precision measurements of physical quantities compared with their classical counterparts. However the ubiquitous decoherence obstructs its application. Recently, non-Markovian effects are shown to be effective in performing quantum optical metrology under locally dissipative environments\cite{PhysRevLett.123.040402}. However, the mechanism is still rather hazy. Here, we uncover the reason why forming a bound state can protect the quantumness against a dissipative ambient via the quantum Fisher information of entangled coherent states. An exact analytical expression of the quantum Fisher information in the long-encoding-time condition is derived, which reveals that the dynamics of precision can asymptotically reach the ideal-case-promised one easily when the average photon number is small. Meanwhile, the scaling exhibits a transition from the weak Heisenberg limit to the sub-classical limit with the increase of average photon number. Our work provides a recipe to realize ultrasensitive measurements in the presence of noise by utilizing non-Markovian effects.