Atomic wave controls of laser-cooled ultra cold atoms

本研究的目的是探讨利用激光控制量子力学原子运动或原子波的基本物理过程和实验技术。在实验上，我研制了用于激光冷却Rb原子的扩展腔半导体激光器系统和用于磁光囚禁Rb原子的玻璃池超高真空系统。利用这些装置，我已经实现了对大约10^8个Rb原子的冷却和俘获，温度大约为几百微开尔文。对这些原子冷却的进一步研究将使利用偏振梯度冷却获得几微开尔文的超冷原子成为可能。因此，在实验上研究激光势场中量子力学原子运动的观测和控制将成为可能。从理论上分析了超冷原子在激光驻波产生的周期势场中的一个基本物理过程，即反冲诱导共振散射。在这种结构中，传输到冷原子上的激光场的强度或相位随原子波包与周期光势的相对位置而变化。因此，使用该方法，可以实时监测光势中的原子运动或量子力学原子状态。这些理论分析合理地解释了我们以前的实验研究反冲诱导共振激光冷却Rb原子。在相同的原子-光组态下，还分析了量子力学对原子运动或原子波的控制，并通过初步实验加以证明。这种对原子运动或原子波的控制将有助于各种原子光学实验。

The purpose of this research is to investigate fundamental physical processes and experimental techniques for control of quantum-mechanical atomic motion or atomic wave using lasers. Experimentally, I have developed extended-cavity diode laser systems for laser cooling of Rb atoms and also a glass cell ultra-high vacuum system for magnet-optical trap of Rb atoms. Using these apparatus, I have realized the cooling and trapping of about 10^8 Rb atoms with a temperature of about several hundreds of micro Kelvin. Further investigation of cooling these atoms will enable to obtain ultra cold atoms at several micro Kelvin using a help of polarization-gradient cooling. Thus, it will experimentally possible to investigate the observation and control of quantum-mechanical atomic motion in a laser light potential. Theoretically, I have analyzed a fundamental physical process of ultra cold atoms in a periodic potential created by laser standing waves, which is called a recoil-induced resonance scattering, In such a configuration, the intensity or phase of the laser field transmitted to the cold atoms change according to the relative position of the atomic wavepacket to the periodic light potential. Thus, using this method, it is possible to monitor the atomic motion or quantum mechanical atomic state in the light potential in real-time. These theoretical analysis reasonably explains our previous experimental study about recoil-induced resonance using laser cooled Rb atoms. The control of quantum mechanical atomic motion or atomic wave has been also analyzed in the same atom-light configuration and it has been demonstrated by our preliminary experiment. Such a control of atomic motion or atomic wave will be useful for various atom optics experiments.