Ke Min(柯敏), Yan Bo(颜波), Cheng Feng(程锋), and Wang Yu-Zhu(王育竹)†
The Laboratory of Quantum Optics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China; Center for Cold Atom Physics, Chinese Academy of Sciences, Shanghai 201800, China
Abstract 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 $\mu$m. 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.
Received: 27 September 2008
Revised: 23 February 2009
Accepted manuscript online:
(Interactions of atoms and molecules with surfaces)
Fund: Project supported by the State Key
Basic Research Program (Grant No 2006CB921202) and the National
Natural Science Foundation of China (Grant No 10334050).
Cite this article:
Ke Min(柯敏), Yan Bo(颜波), Cheng Feng(程锋), and Wang Yu-Zhu(王育竹) Surface-induced evaporative cooling 2009 Chin. Phys. B 18 4274
Bose--Einstein condensation on an atom chip Yan Bo(颜波), Cheng Feng(程峰), Ke Min(柯敏), Li Xiao-Lin(李晓林), Tang Jiu-Yao(唐九耀), and Wang Yu-Zhu(王育竹). Chin. Phys. B, 2009, 18(10): 4259-4263.
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