Rashid Muddassar, Tufarelli Tommaso, Bateman James, Vovrosh Jamie, Hempston David, Kim M S, Ulbricht Hendrik
Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, United Kingdom.
School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Phys Rev Lett. 2016 Dec 30;117(27):273601. doi: 10.1103/PhysRevLett.117.273601.
We experimentally squeeze the thermal motional state of an optically levitated nanosphere by fast switching between two trapping frequencies. The measured phase-space distribution of the center of mass of our particle shows the typical shape of a squeezed thermal state, from which we infer up to 2.7 dB of squeezing along one motional direction. In these experiments the average thermal occupancy is high and, even after squeezing, the motional state remains in the remit of classical statistical mechanics. Nevertheless, we argue that the manipulation scheme described here could be used to achieve squeezing in the quantum regime if preceded by cooling of the levitated mechanical oscillator. Additionally, a higher degree of squeezing could, in principle, be achieved by repeating the frequency-switching protocol multiple times.
我们通过在两个捕获频率之间快速切换，对光学悬浮纳米球的热运动状态进行了实验性压缩。我们测量的粒子质心的相空间分布呈现出压缩热态的典型形状，由此我们推断在一个运动方向上的压缩高达2.7分贝。在这些实验中，平均热占据率很高，并且即使在压缩之后，运动状态仍处于经典统计力学的范围内。然而，我们认为，如果在此之前对悬浮的机械振荡器进行冷却，这里描述的操纵方案可用于在量子 regime 中实现压缩。此外，原则上通过多次重复频率切换协议可以实现更高程度的压缩。
