Cavity Cooling Below the Recoil Limit
Cavity Cooling Below the Recoil Limit
复制标题
DOI：
10.1126/science.1219166
复制
发表时间：
2012-07
期刊：
影响因子：
56.9
通讯作者：
M. Wolke;Julian Klinner;H. Keßler;A. Hemmerich
中科院分区：
文献类型：
--
作者：
M. Wolke;Julian Klinner;H. Keßler;A. Hemmerich
冷先生激光冷却原子依赖于特定结构的电子跃迁的存在，使其在相对低密度的有限数量的原子物种中变得实用。替代方法包括涉及光学腔的那些方法，其中原子-腔相互作用使得能够在不需要共振跃迁的情况下进行冷却。Wolke等人（第75页）提出了这样一种冷却方案，用于加热然后冷却Rb原子的玻色-爱因斯坦凝聚体。该方法应适用于较热的样品，其中需要使用不同频率的激光脉冲序列。铷原子在窄带光腔中通过单光子吸收和发射被加热和冷却。传统的激光冷却依赖于近共振光的重复电子激发，这将其应用领域限制在以中等颗粒密度制备的选定数量的原子物种上。具有足够大的珀塞尔因子的光学腔允许激光器冷却方案，从而避免这些限制。在这里，我们报告一个原子腔系统，结合珀塞尔因子高于40与腔带宽低于反冲频率与动能转移在一个单光子散射事件。这使我们能够进入一个尚未探索的原子-腔相互作用机制，其中原子运动可以通过亚反冲分辨率的目标耗散来操纵。我们证明了腔诱导加热的玻色-爱因斯坦凝聚体和随后的冷却粒子密度和温度与传统的激光冷却不兼容。
Mr. Cool Laser cooling of atoms relies on the presence of electronic transitions of specific structure, making it practical for a limited number of atomic species at relatively low densities. Alternative methods include those involving optical cavities, where atom-cavity interaction enables cooling without the need for resonant transitions. Wolke et al. (p. 75) present such a cooling scheme that was used to heat and then cool a Bose-Einstein condensate of Rb atoms. The method should be applicable to hotter samples where a sequence of laser pulses of different frequencies would need to be used. Rubidium atoms are heated and cooled by single-photon absorption and emission in a narrow-bandwidth optical cavity. Conventional laser cooling relies on repeated electronic excitations by near-resonant light, which constrains its area of application to a selected number of atomic species prepared at moderate particle densities. Optical cavities with sufficiently large Purcell factors allow for laser cooling schemes, avoiding these limitations. Here, we report on an atom-cavity system, combining a Purcell factor above 40 with a cavity bandwidth below the recoil frequency associated with the kinetic energy transfer in a single photon scattering event. This lets us access a yet-unexplored regime of atom-cavity interactions, in which the atomic motion can be manipulated by targeted dissipation with sub-recoil resolution. We demonstrate cavity-induced heating of a Bose-Einstein condensate and subsequent cooling at particle densities and temperatures incompatible with conventional laser cooling.