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arXiv 0905.3729quant-ph
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亚海森堡精度探测宏观量子态

Probing macroscopic quantum states with a sub-Heisenberg accuracy

Haixing Miao, Stefan Danilishin, Helge Muller-Ebhardt, Henning Rehbein, Kentaro Somiya, Yanbei Chen

摘要:

在降低经典本底噪声方面取得的重大成就将允许宏观系统通过连续测量(即条件化)制备接近海森伯极限的量子态。为了探测条件量子态和确认量子动力学,我们提出了一种最佳的时域变分测量,其中零差检测相位随时间变化。该协议允许我们表征低于海森堡不确定性的宏观量子态-即量子断层扫描-并且唯一的限制来自读出损耗,其以与Kimble等人提出的频域变分方案类似的方式进入。在没有读出损失的情况下,它与Vyatchanin等人发明的用于检测具有已知到达时间的引力波(GW)信号的反作用回避方案相同。作为一个特殊的例子,并激励宏观量子力学(MQM)实验与未来的GW探测器,我们主要集中在自由质量限制-特征测量频率远高于振荡器频率-并进一步假设经典噪声是马尔可夫的,它捕获了宽带GW探测器的主要特征。此外,我们考虑在GW探测器中验证宏观测试质量之间的Einstein-Podolsky-Rosen(EPR)型纠缠,这使得能够测试Diosi和Penrose提出的一个特定版本的引力退相干。

英文摘要:

Significant achievements in the reduction of classical-noise floor will allow macroscopic systems to prepare nearly Heisenberg-Limited quantum states through a continuous measurement, i.e. conditioning. In order to probe the conditional quantum state and confirm quantum dynamics, we propose use of an optimal time-domain variational measurement, in which the homodyne detection phase varies in time. This protocol allows us to characterize the macroscopic quantum state below the Heisenberg Uncertainty -- i.e. Quantum Tomography -- and the only limitation comes from readout loss which enters in a similar manner as the frequency-domain variational scheme proposed by Kimble et al.. In the case of no readout loss, it is identical to the back-action-evading scheme invented by Vyatchanin et al. for detecting gravitational-wave (GW) signal with known arrival time. As a special example and to motivate Macroscopic Quantum Mechanics (MQM) experiments with future GW detectors, we mostly focus on the free-mass limit -- the characteristic measurement frequency is much higher than the oscillator frequency -- and further assume the classical noises are Markovian, which captures the main feature of a broadband GW detector. Besides, we consider verifications of Einstein-Podolsky-Rosen (EPR) type entanglements between macroscopic test masses in GW detectors, which enables to test one particular version of Gravity Decoherence conjectured by Diosi and Penrose.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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