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Quantum Optics with Cold Atoms (Inhibition of Spontaneous Emission, Quantum Zeno Effect, and Bose-Einstein Condensation)

冷原子量子光学（自发发射抑制、量子芝诺效应和玻色-爱因斯坦凝聚）

基本信息

批准号：
09440150
负责人：
KUGA Takahiro
金额：
$ 7.94万
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 (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

We achieved the Bose-Einstein condensation (BEC) of rubidium atomic gas in 1998, which is the first success in Japan and 16th in the world. After the first success of BEC, we concentrated our interests to coherent properties of matter waves. We constructed a Mach-Zehnder interferometer for matter waves by utilizing Bragg diffraction and successfully observed the interference fringes with 100% contrast. This result clarified and confirmed the perfect first order coherence of the condensed atoms. We also performed a coherent matter wave amplification with condensed atoms. A small fraction (about 6%) of BEC atoms was diffracted by a Bragg pulse and non-resonant laser on the BEC could amplify the matter wave by a factor of 10. We verified that the phase of matter wave was conserved through this amplification process using our Mach-Zehnder interferometer for mater waves.The strong atom-photon coupling generated inside high-finesse optical micro cavity lets us detect a single atom trajectory in real time. Such a strong coupling is a candidate for trapping a single atom with a single photon, which is very suitable to realize quantum gate, single photon generator, and so on. Several preliminary experimental results have already been reported. However, they are limited to the use of longitudinal cavity mode. We proposed and constructed a novel type of single-atom trapping using a high-order transverse mode of the cavity. We observed the signal from single atoms with a fairly good signal to noise ratio. Now we are trying to trap single atoms with single photons in TEMィイD201ィエD2 mode of the micro cavity.

1998年，我们成功地实现了玻色-爱因斯坦凝聚(BEC)，这在日本是第一次，在世界上也是第16次。在BEC第一次取得成功后，我们把兴趣集中在物质波的相干性质上。我们利用布拉格衍射搭建了物质波的马赫-曾德尔干涉仪，并以100%的对比度成功地观测到了干涉条纹。这一结果澄清并证实了凝聚原子的完美一阶相干性。我们还用凝聚原子进行了相干物质波放大。用Bragg脉冲对一小部分BEC原子(约6%)进行衍射，BEC上的非共振激光可以将物质波放大10倍。我们利用我们的Mach-Zehnder干涉仪对物质波进行了放大，验证了物质波的相位是守恒的。在高精细光学微腔内产生的强原子-光子耦合使我们能够实时检测单个原子的轨迹。这样的强耦合是用单光子囚禁单原子的候选方案，非常适合实现量子门、单光子发生器等。已经报道了几个初步的实验结果。然而，它们仅限于使用纵腔模式。我们提出并构造了一种新型的利用腔的高阶横模的单原子陷阱。我们观察到了来自单个原子的信号，具有相当好的信噪比。现在，我们正尝试在微腔的瞬变电子显微镜ィイD201ィエD2模中用单光子囚禁单原子。