标题： 低于量子散粒噪声的引力波探测 显示英文标题

标题： Exposing Gravitational Waves below the Quantum Shot Noise

摘要： 地面引力波（GW）探测器的灵敏度在几百赫兹及以上受到量子散粒噪声的限制。然而，可以使用Martynov等人提出的量子关联技术[Phys. Rev. A 95, 043831 (2017)] 来消除散粒噪声的期望值，从而揭示由引力波干涉仪反相端口交叉相关两个输出形成的交叉频谱中的潜在经典信号。我们在此探讨了利用量子关联检测天体物理引力波信号的前景，并分析了其灵敏度。从概念上讲，这项技术类似于两个不同引力波探测器的相关性，因为它利用了引力波信号会在两个输出中相关联但散粒噪声不会相关的事实。量子关联也有其独特的优势，因为它只需要一个干涉仪即可完成检测。因此，量子关联可以提高工作周期，增强搜索效率，并能够检测高度极化的信号。特别是，我们展示了量子关联对于检测双中子星合并后的残骸（具有短时长（$< 1\,{\rm s}$）和中间时长（$\sim 10-10^4\,{\rm s}$））以及设定未知脉冲星连续发射的上限尤其有用。 显示英文摘要

摘要： The sensitivities of ground-based gravitational-wave (GW) detectors are limited by quantum shot noise at a few hundred Hertz and above. Nonetheless, one can use a quantum-correlation technique proposed by Martynov, et al. [Phys. Rev. A 95, 043831 (2017)] to remove the expectation value of the shot noise, thereby exposing underlying classical signals in the cross spectrum formed by cross-correlating the two outputs in a GW interferometer's anti-symmetric port. We explore here the prospects and analyze the sensitivity of using quantum correlation to detect astrophysical GW signals. Conceptually, this technique is similar to the correlation of two different GW detectors as it utilizes the fact that a GW signal will be correlated in the two outputs but the shot noise will be uncorrelated. Quantum correlation also has its unique advantages as it requires only a single interferometer to make a detection. Therefore, quantum correlation could increase the duty cycle, enhance the search efficiency, and enable the detection of highly polarized signals. In particular, we show that quantum correlation could be especially useful for detecting post-merger remnants of binary neutron stars with both short ($< 1\,{\rm s}$) and intermediate ($\sim 10-10^4\,{\rm s}$) durations and setting upper limits on continuous emissions from unknown pulsars.