Squeezed Vacuum Used to Accelerate the Search for a Weak Classical Signal
Squeezed Vacuum Used to Accelerate the Search for a Weak Classical Signal
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DOI：
10.1103/physrevx.9.021023
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发表时间：
2019-05-03
影响因子：
12.5
通讯作者：
Lehnert, K. W.
中科院分区：
文献类型：
--
作者：
Malnou, M.;Palken, D. A.;Lehnert, K. W.
许多质疑基础理论的实验需要探测器，其灵敏度受到量子力学定律的限制。在基于空腔的轴子暗物质搜索中，空腔电磁场两个正交的真空涨落限制了对轴子感应场的灵敏度。在设计用于部分模仿现有轴子探测器的装置中，我们通过实验证明可以通过使用压缩态来克服这种量子限制。通过准备处于压缩状态的微波腔并仅测量压缩正交，我们将频谱扫描速率提高了 2.12 +/- 0.08 倍。这种增强与解释不完美挤压和测量的理论模型在数量上非常一致。
Many experiments that interrogate fundamental theories require detectors whose sensitivities are limited by the laws of quantum mechanics. In cavity-based searches for axionic dark matter, vacuum fluctuations in the two quadratures of the cavity electromagnetic field limit the sensitivity to an axion-induced field. In an apparatus designed to partially mimic existing axion detectors, we demonstrate experimentally that such quantum limits can be overcome through the use of squeezed states. By preparing a microwave cavity in a squeezed state and measuring just the squeezed quadrature, we enhance the spectral scan rate by a factor of 2.12 +/- 0.08. This enhancement is in excellent quantitative agreement with a theoretical model accounting for both imperfect squeezing and measurement.