Surface-induced evaporative cooling  

作　　者：柯敏 颜波 程锋 王育竹 

机构地区：[1]The Laboratory of Quantum Optics, Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences [2]Center for Cold Atom Physics, Chinese Academy of Sciences

出　　处：《Chinese Physics B》2009年第10期4274-4280,共7页中国物理B（英文版）

基　　金：Project supported by the State Key Basic Research Program (Grant No 2006CB921202);the National Natural Science Foundation of China (Grant No 10334050)

摘　　要：The effects of surface-induced evaporative cooling on an atom chip are investigated. The evolutions of temperature, number and phase-space density of the atom cloud are measured when the atom cloud is brought close to the surface. Rapid decrease of the temperature and number of the atoms is found when the atom-surface distance is 〈 100 ttm. A gain of about a factor of five on the phase-space density is obtained. It is found that the efficiency of the surface-induced evaporative cooling depends on the atom-surface distance and the shape of the evaporative trap. When the atoms are moved very close to the surface, severe heating is observed, which dominates when the holding time is 〉 8 ms. It is important that the surface-induced evaporative cooling offers novel possibilities for the realization of a continuous condensation, where a spatially varying evaporative cooling is required.The effects of surface-induced evaporative cooling on an atom chip are investigated. The evolutions of temperature, number and phase-space density of the atom cloud are measured when the atom cloud is brought close to the surface. Rapid decrease of the temperature and number of the atoms is found when the atom-surface distance is 〈 100 ttm. A gain of about a factor of five on the phase-space density is obtained. It is found that the efficiency of the surface-induced evaporative cooling depends on the atom-surface distance and the shape of the evaporative trap. When the atoms are moved very close to the surface, severe heating is observed, which dominates when the holding time is 〉 8 ms. It is important that the surface-induced evaporative cooling offers novel possibilities for the realization of a continuous condensation, where a spatially varying evaporative cooling is required.

关 键 词：atom chip atom-surface distance surface-induced evaporative cooling 

分 类 号：O562[理学—原子与分子物理]