论文标题
图书馆反馈冷却
Librational Feedback Cooling
论文作者
论文摘要
在光学捕获的二氧化硅微球中，可以观察到刚体在首选方向周围进行角振荡的库运动。我们证明了一种$ \ sim 5〜μ $ m直径球的冷却自由度的冷却，这些球体被诱导与外部电场旋转，并旋转与电动偶极矩相结合。通过向旋转场添加相位调制来完成冷却。通过将$π/2 $换档应用于电场的相位并拟合库运动的指数衰减以获得阻尼时间，并估算从观察到的平衡中的模式温度估算模式温度，可以量化冷却程度。结果是研究捕获的微球动力学的重要一步，对于将机械运动冷却至基态以及在微观尺度上提供了有关材料中电荷迁移率的见解。
Librational motion, whereby a rigid body undergoes angular oscillation around a preferred direction, can be observed in optically trapped, silica microspheres. We demonstrate the cooling of one librational degree of freedom for $\sim 5~μ$m diameter spheres that have been induced to rotate with an external electric field coupled to their electric dipole moment. Cooling is accomplished by adding a phase modulation to the rotating field. The degree of cooling is quantified by applying a $π/2$ shift to the phase of the electric field and fitting the resulting exponential decay of the librational motion to obtain a damping time, as well as estimating a mode temperature from the observed libration in equilibrium. The result is an important step in the study of the dynamics of trapped microspheres, crucial to cooling the mechanical motion to its ground state, as well as providing insights regarding the charge mobility in the material at microscopic scales.
