Force and acceleration sensing with optically levitated nanogram masses at microkelvin temperatures
Force and acceleration sensing with optically levitated nanogram masses at microkelvin temperatures
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DOI：
10.1103/physreva.101.053835
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发表时间：
2020-05-15
影响因子：
2.9
通讯作者：
Moore, David C.
中科院分区：
文献类型：
--
作者：
Monteiro, Fernando;Li, Wenqiang;Moore, David C.
本文演示了通过最小化捕获激光的技术指向噪声，将直径为10 μ m的光学悬浮二氧化硅球的质心运动冷却到50 +/- 22 μ K的有效温度。这种低噪声导致加速度和力灵敏度分别为95 +/- 41 ng/根Hz （g = 9.8 m/s(2)）和0.95 +/- 0.11 an /根Hz，频率接近50 Hz。这种力灵敏度与光学悬浮纳米球的力灵敏度相当，光学悬浮纳米球的质量比光学悬浮纳米球小10(4)倍，相应的加速度灵敏度比光学悬浮纳米球好几个数量级。进一步表明，在这些条件下，球体在超过一天的时间内稳定地保持在类似于10（-7）毫巴的压力下，没有主动冷却。在中压条件下，反馈冷却仍然是必要的，这推动了对微球损失机制的全面研究，并为真空中无反馈光捕获的要求提供了更好的理解。这项工作可以实现对作用于微米级质量的加速度和力的高灵敏度搜索，包括那些可能由超越标准模型的新物理学产生的加速度和力。
This paper demonstrates cooling of the center-of-mass motion of 10-mu m-diameter optically levitated silica spheres to an effective temperature of 50 +/- 22 mu K, achieved by minimizing the technical pointing noise of the trapping laser. This low noise leads to an acceleration and force sensitivity of 95 +/- 41 ng/root Hz (g = 9.8 m/s(2)) and 0.95 +/- 0.11 aN/root Hz, respectively, at frequencies near 50 Hz. This force sensitivity is comparable to that demonstrated for optically levitated nanospheres that are 10(4) times less massive, corresponding to an acceleration sensitivity that is several orders of magnitude better. It is further shown that under these conditions the spheres remain stably trapped at pressures of similar to 10(-7) mbar with no active cooling for periods longer than a day. Feedback cooling is still necessary in the moderate-pressure regime, motivating a comprehensive study of the loss mechanisms of the microspheres and providing better understanding of the requirements for feedback-free optical trapping in vacuum. This work can enable high-sensitivity searches for accelerations and forces acting on micron-sized masses, including those that could be produced by new physics beyond the standard model.