Cavity cooling of a microlever
Cavity cooling of a microlever
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DOI：
10.1038/nature03118
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发表时间：
2004-12-23
期刊：
影响因子：
64.8
通讯作者：
Karrai, K
中科院分区：
文献类型：
--
作者：
Metzger, CH;Karrai, K
最近，在宏观物体和光子之间实现纠缠量子态 (1) 的前景激发了人们对新激光冷却方案 (2,3) 的兴趣。例如，镜面振动模式的激光冷却可以通过将其置于辐射 (2) 或光热 (4) 压力下来实现，通过伺服环路主动控制，调整伺服环路以对抗预设频率窗口内的布朗热运动。相比之下，原子可以在没有这种主动反馈的情况下被动激光冷却，因为它们的随机运动通过与辐射的相互作用而本质上受到阻尼(5-8)。在这里，我们报告了微机械谐振器的无源（或内在）光学冷却的直接实验证据。我们利用空腔诱发的光热压力来淬灭镀金硅微杆的布朗振动涨落，从室温降低到 18 K 的有效温度。将该方法扩展到光腔诱发的辐射压力可能能够达到量子极限，为涉及 10(14) 数量级原子的宏观量子叠加态 (1) 的实验研究开辟道路。
The prospect of realizing entangled quantum states between macroscopic objects and photons(1) has recently stimulated interest in new laser-cooling schemes(2,3). For example, laser-cooling of the vibrational modes of a mirror can be achieved by subjecting it to a radiation(2) or photothermal(4) pressure, actively controlled through a servo loop adjusted to oppose its brownian thermal motion within a preset frequency window. In contrast, atoms can be laser-cooled passively without such active feedback, because their random motion is intrinsically damped through their interaction with radiation(5-8). Here we report direct experimental evidence for passive ( or intrinsic) optical cooling of a micromechanical resonator. We exploit cavity-induced photothermal pressure to quench the brownian vibrational fluctuations of a gold-coated silicon microlever from room temperature down to an effective temperature of 18 K. Extending this method to optical-cavity-induced radiation pressure might enable the quantum limit to be attained, opening the way for experimental investigations of macroscopic quantum superposition states(1) involving numbers of atoms of the order of 10(14).