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Physics of Laser Cooling and Atomic Gas BEC

激光冷却和原子气体 BEC 物理

基本信息

批准号：
11216201
负责人：
KUGA Takahiro
金额：
$ 89.79万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2002
项目状态：
已结题

项目摘要

The main achievement of the A3 project was the physics related to the rubidium atoms BEC. The A3 was operated by three groups. Kuga et al worked on (1) the first realization of BEC in Japan, (2) physics related to the BEC, (3) the development of an improved BEC apparatus, and (4) the cavity quantum electrodynamics that combines a laser cooled atom and a microcavity. (1) The BEC was achieved, first, by collecting pre-cooled Rb atoms under a high vacuum, transferring atoms into a magnetic trap, adiabatically compress the atomic cloud, and then, by evaporative cooling. (2) Three experiments were done. (I) the diffraction of BEC atoms in a standing wave of light that demonstrated Raman-Nath, Bragg, and Stern-Gerlach type diffractions. (ii) Demonstration of a Mach Zhender type atom interferometer. (iii) The amplification of a coherent atomic wave by using atom-photon four wave mixing. (3) To increase the luminosity of the BEC, they developed a Zeeman slower that can supply 10^11 atoms per seconds continuously at the speed of 20m/s. (4) Approximately 10 laser cooled Rb atoms were introduced into a micro-cavity of 70microm meter spacing. They observed both subliminal and superliminal propagations of a laser pulse through the cavity. Hirano et al worked on the physics of the Rb BEC. (1) Dynamics of BEC when an uniform off-resonant laser beam is illuminated. (2) The oscillation of BEC cloud in a single beam optical dipole trap. Sasada et al developed a new type of cold metastable He atomic beam source that was obtained through the discharge of cryogenically cooled helium gas. They worked also on the Laguerre-Gauss laser beam that is to be used for a dark optical trap and guide.

A3项目的主要成果是与Rb原子BEC有关的物理。A3分三组进行操作。Kuga等人致力于(1)在日本首次实现BEC，(2)与BEC相关的物理学，(3)改进的BEC仪器的开发，以及(4)结合激光冷却原子和微腔的腔量子电动力学。(1)BEC是通过在高真空下收集预冷的Rb原子，将原子转移到磁陷阱中，对原子云进行绝热压缩，然后通过蒸发冷却实现的。(2)进行了三个实验。(I)BEC原子在驻波光中的衍射，表现出拉曼-纳特、布拉格和斯特恩-格拉赫类型的衍射。(Ii)马赫-真德型原子干涉仪的演示。(Iii)利用原子-光子四波混频放大相干原子波。(3)为了提高BEC的亮度，他们研制了塞曼慢化器，可以以20m/S的速度连续提供每秒10^11个原子。(4)将大约10个激光冷却的Rb原子引入到一个间距为70微米的微腔中。他们观察到了激光脉冲在腔体中的阈值下和阈值上的传播。平野等人致力于RB BEC的物理研究。(1)均匀非共振激光照射下BEC的动力学特性。(2)单光束光偶极子陷阱中BEC云的振荡。Sasada等人开发了一种新型的冷亚稳态氦原子束光源，该光源是通过放电低温冷却的氦气体获得的。他们还研究了拉盖尔-高斯激光光束，该光束将用于暗光学陷阱和导光。