Surface-induced evaporative cooling

• 来源期刊: 中国物理B（英文版）
• 关键词: atom chip atom-surface distance surface-induced evaporative cooling
• 年，卷（期）: 2009,（10）
• 页码范围: 4274-4280
• 页数: 7页
• 语种: 英文

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 μm. 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.