论文标题
40k原子的退化拉曼边带冷却
Degenerate Raman sideband cooling of 40K atoms
论文作者
论文摘要
我们报告了$^{40} $ k原子的退化拉曼边带冷却的实现。该方案结合了一个3D光学晶格，该晶格限制了原子并驱动拉曼过渡。光冷却周期通过两个光学泵梁封闭。形成晶格的激光梁的波长接近D $ _2 $原子过渡，而光泵仪则在D $ _1 $过渡附近进行。通过这种冷却方法，我们达到了$ \ sim $$1μ$ k的温度，$ \ sim $$ 10^7 $原子。这对应于$ \ ge $$ 10^{ - 3} $的相位空间密度。此外，费米子集合旋转到有利于随后蒸发冷却的条件。我们研究了冷却方案对多个参数的依赖性，包括施加的磁场，光泵梁的失谐，持续时间和强度曲线。将这个光冷却阶段添加到当前的费米气体实验可以改善最终条件并提高数据速率。
We report on the implementation of degenerate Raman sideband cooling of $^{40}$K atoms. The scheme incorporates a 3D optical lattice, which confines the atoms and drives the Raman transitions. The optical cooling cycle is closed by two optical pumping beams. The wavelength of the laser beams forming the lattice is close to the D$_2$ atomic transition, while the optical pumping is operated near the D$_1$ transition. With this cooling method, we achieve temperature of $\sim$$1μ$K of a cloud with $\sim$$10^7$ atoms. This corresponds to a phase space density of $\ge$$10^{-3}$. Moreover, the fermionic ensemble is spin polarized to conditions which are favorable for subsequent evaporative cooling. We study the dependence of the cooling scheme on several parameters, including the applied magnetic field, the detuning, duration, and intensity profile of the optical pumping beams. Adding this optical cooling stage to current Fermi gas experiments can improve the final conditions and increase the data rate.
