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

我们在1998年实现了橡胶原子气体的博斯-爱因斯坦浓缩（BEC），是日本第一次成功，也是世界第16次成功。在BEC的第一次成功之后，我们集中了我们对物质波的相关性质的兴趣。我们为物质波构建了一个Mach-Zehnder干扰计，使Bragg产生了有效的差异，并成功地观察到了与100%对比的干扰fringes。这一结果已澄清并确认了浓缩原子的完美第一顺序一致性。我们也用浓缩原子进行了相干物质波放大。BEC原子的一小部分（约6%）被布拉格脉冲和非共振激光器所影响，BEC可以通过10个因素的影响来增强重要波。我们验证了物质波的相位，因为我们使用我们的Mach-Zehnder干涉仪的放大过程。强原子-光子耦合产生了内部高精细光学微洞穴，我们在实时中检测到一个单一的原子轨迹。这样一个强耦合是用单光子欺骗单原子的可能性，是非常适合实现量子门、单光子发生器和其他方面的。一些初步实验结果已经报告过。However，它们是有限的，只能用于纵向洞穴模式。我们提出并构建了一种新颖的单原子陷阱类型，使用一种高顺序反向模式的洞穴。我们从单个原子中观察到了一个相当好的信号到噪音比率的信号。Now we are trying to trap single atoms with single photons in TEM中的D201-D2 mode of the micro cavity。

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.