论文标题
朝向悬浮的光学力学中的定向力传感
Towards directional force sensing in levitated optomechanics
论文作者
论文摘要
悬浮的纳米颗粒正在从两个不同的角度进行深入研究：作为宏观量子相干性的潜在实现；作为超敏感的力传感器，一直到Zeptonewton级别，并具有各种应用，包括搜索暗物质。未来的目的是合并这两条线，从而使量子受限传感器的发展。在这里，我们提出机械互相关光谱$ s_ {xy}（ω）$提供新的可能性：一旦将探测器错位错误最小化，$ s_ {xy}（ω）$的光谱形状直接指出了外部随机力的方向，从而提供了类似于$ x-y $ x-y $ x-y $ x-y $ $ x-y $ $ x-y $ $ x-y $ $ x-y $ $ x-y $ $ x-y $ $ x-y $ x-y $ $ x-y $ $ x-y $ $ x-y $ $ x-y $ $ x-y $ $ x-y $ $ x-y $ $ $ x-y $ $的方向的方向。我们分析了这一点以检测微观气流，但是任何广泛的定向力都足够了，可以直接通过具有或没有空腔的实验室测试力进行直接研究。对于空腔设置，我们分析了由于掩盖定向力的特征的光学反向作用而引起的检测器和运动模式之间的未对准不确定性，并显示了如何抑制它们。接近量子制度，我们由于量子射击噪声不精确的$ x-y $相关效果而量化了不精确。
Levitated nanoparticles are being intensively investigated from two different perspectives: as a potential realisation of macroscopic quantum coherence; and as ultra-sensitive sensors of force, down to the zeptoNewton level, with a range of various applications, including the search for Dark Matter. A future aim is to merge these two strands, enabling the development of quantum-limited sensors. Here we propose that mechanical cross-correlation spectra $S_{xy}(ω)$ offer new possibilities: once detector misalignment errors are minimised, the spectral shape of $S_{xy}(ω)$ directly points out the orientation of an external stochastic force, offering something akin to a compass in the $x-y$ plane. We analyse this for detection of microscopic gas currents, but any broad spectrum directed force will suffice, enabling straightforward investigation with laboratory test forces with or without cavities. For a cavity set-up, we analyse misalignment imprecisions between detectors and motional modes due to for example optical back-actions that mask the signature of the directed forces, and show how to suppress them. Near quantum regimes, we quantify the imprecision due to the $x-y$ correlating effect of quantum shot noise imprecision.
