Quantum metrology with generalized cat states
Quantum metrology with generalized cat states
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DOI：
10.1103/physreva.100.032318
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发表时间：
2019-09
影响因子：
2.9
通讯作者：
Mamiko Tatsuta;Y. Matsuzaki;A. Shimizu
中科院分区：
文献类型：
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作者：
Mamiko Tatsuta;Y. Matsuzaki;A. Shimizu
我们展示了在量子计量学中宏观上不同的状态的叠加和灵敏度之间的一般关系。广义猫态是通过使用一个索引，提取宏观不同的状态之间的相干性，和各种各样的状态，包括一个经典的混合指数大量的状态，已被确定为广义猫态与此标准。我们发现，如果我们使用广义猫态的磁场传感没有噪音，灵敏度达到海森堡标度。更重要的是，我们甚至证明了广义猫态的灵敏度在退相效应下达到了超越标准量子极限的极限标度灵敏度。作为一个例子，我们调查的敏感性，是通过一个单一的全球操纵的热平衡状态，并找到一个改进的几个数量级从以前的传感器的广义猫状态。澄清一个广泛的类，包括这样一个特殊的状态计量有用的，我们的研究结果显着拓宽量子计量学的潜力。
We show a general relationship between a superposition of macroscopically distinct states and sensitivity in quantum metrology. Generalized cat states are defined by using an index which extracts the coherence between macroscopically distinct states, and a wide variety of states, including a classical mixture of an exponentially large number of states, has been identified as the generalized cat state with this criterion. We find that if we use the generalized cat states for magnetic field sensing without noise, the sensitivity achieves the Heisenberg scaling. More importantly, we even show that sensitivity of generalized cat states achieves the ultimate scaling sensitivity beyond the standard quantum limit under the effect of dephasing. As an example, we investigate the sensitivity of a generalized cat state that is attainable through a single global manipulation on a thermal equilibrium state and find an improvement of a few orders of magnitude from the previous sensors. Clarifying a wide class that includes such a peculiar state as metrologically useful, our results significantly broaden the potential of quantum metrology.