Cooling-by-measurement and mechanical state tomography via pulsed optomechanics
Cooling-by-measurement and mechanical state tomography via pulsed optomechanics
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DOI：
10.1038/ncomms3295
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发表时间：
2013-08-01
影响因子：
16.6
通讯作者：
Aspelmeyer, M.
中科院分区：
文献类型：
--
作者：
Vanner, M. R.;Hofer, J.;Aspelmeyer, M.
观察物理量而不干扰它是控制单个量子系统的关键能力。这种反作用规避或量子非破坏测量在20世纪70年代首次引入引力波探测，现在这种技术是整个量子科学中不可或缺的工具。在这里，我们使用持续时间比机械运动周期短得多的光脉冲来测量机械振荡器的位置。利用这种反作用回避相互作用，我们证明了状态准备和全状态断层扫描的机械运动状态。我们已经重建了位置不确定性降低到19 pm的状态，受到光脉冲量子波动的限制，我们已经进行了“测量冷却”，将机械模式温度从初始的1，100降低到16 K。未来对这项技术的改进将允许量子压缩的机械运动，甚至从室温，和重建非经典状态表现出负相空间准概率。
Observing a physical quantity without disturbing it is a key capability for the control of individual quantum systems. Such back-action-evading or quantum non-demolition measurements were first introduced in the 1970s for gravitational wave detection, and now such techniques are an indispensable tool throughout quantum science. Here we perform measurements of the position of a mechanical oscillator using pulses of light with a duration much shorter than a period of mechanical motion. Utilizing this back-action-evading interaction, we demonstrate state preparation and full state tomography of the mechanical motional state. We have reconstructed states with a position uncertainty reduced to 19 pm, limited by the quantum fluctuations of the optical pulse, and we have performed 'cooling-by-measurement' to reduce the mechanical mode temperature from an initial 1,100 to 16 K. Future improvements to this technique will allow for quantum squeezing of mechanical motion, even from room temperature, and reconstruction of non-classical states exhibiting negative phase-space quasi-probability.