Laser Cooling and Fundamental Physics

A2小组的研究项目的最终目标是通过使用激光冷却原子来验证物理学的基本定律。为此，Yabuzaki等人致力于Yb原子的激光冷却和捕获，RB玻色凝聚的改进以及量子非破坏测量的理论工作。在Yb冷却计划中，他们实现了（1）在磁光阱中捕获超冷Yb原子，（2）实现超高亮度的Yb原子阱，（3）观察玻色子和费米子Yb原子混合物中的合作冷却，（4）在光偶极阱中的高效冷却，（5）通过光缔合产生超冷Yb分子，（6）Yb原子的第一非简并BEC。在铷计划中，他们通过将冷却的Rb原子转移到二氧化碳激光器的交叉光束光学偶极阱中，在蒸发冷却的几秒钟内成功地产生了稳定的BEC。此外，他们还研究了在光学偶极阱中带来意想不到的高密度的物理学。森田的团队是世界上第一个捕获亚稳态He-3的团队。他们研究超冷He-4和He-3原子的碰撞动力学。他们解决了He-3碰撞截面大于He-4碰撞截面的机制，Kitano等人研究了反量子Zeno效应和光在负群速度介质中的传播。

The ultimate goal of the research project of the A2 group was to verify fundamental laws of physics by using laser cooled atoms. For this purpose Yabuzaki et al worked on the laser cooling and trapping of Yb atoms, improvement of RB Bose condensates, and theoretical work on the quantum non-demolition measurements. On the Yb cooling program, they achieved (1) trapping of ultra- cold Yb atoms in a magneto-optical trap, (2) realization of the Yb atomic trap of ultra-high luminocity, (3) observation of cooperative cooling in the mixture of bosonic and fermionic Yb atoms, (4) highly efficient cooling in an optical dipole trap, (5) generation of ultra-cold Yb molecules by photoassociation, (6) the first non-degenerate BEC of Yb atoms. On the rubidium program, they succeeded generating stable BEC within few seconds of evaporative cooling by transferring cooled Rb atoms into a crossed-beam optical dipole trap of a carbon dioxide laser. Further, they study physics that brings an unexpectedly high density in optical dipole trap. Morita's group was the first to trap metastable He-3 in the world. They study collision dynamics of ultracold He-4 and He-3 atoms. They solved me mechanism that makes the collision cross section of He-3 larger than that of He-4, Kitano et al studied anti-quantum Zeno effect and the propagation of light through a medium with negative group velocity.