Steinecker Matthew H, McCarron Daniel J, Zhu Yuqi, DeMille David
Department of Physics, Yale University, 217 Prospect St, New Haven, CT, 06511, USA.
Chemphyschem. 2016 Nov 18;17(22):3664-3669. doi: 10.1002/cphc.201600967. Epub 2016 Nov 8.
We report the production of ultracold, trapped strontium monofluoride (SrF) molecules with number density and phase-space density significantly higher than previously achieved. These improvements are enabled by three distinct changes to our recently-demonstrated scheme for radio-frequency magneto-optical trapping of SrF: modification of the slowing laser beam geometry, addition of an optical pumping laser, and incorporation of a compression stage to the magneto-optical trap. With these improvements, we observe a trapped sample of SrF molecules at density 2.5×10 cm and phase-space density 6×10 , each a factor of 4 greater than in previous work. Under different experimental conditions, we observe trapping of up to 10 molecules, a factor of 5 greater than in previous work. Finally, by reducing the intensity of the applied trapping light, we observe molecular temperatures as low as 250 μK.
我们报告了超冷、被俘获的一氟化锶（SrF）分子的产生，其数密度和相空间密度显著高于此前所达到的水平。这些改进是通过对我们最近展示的用于射频磁光俘获SrF的方案进行三个不同的改变实现的：修改减速激光束的几何形状、添加光泵浦激光器以及在磁光阱中加入一个压缩阶段。有了这些改进，我们观察到被俘获的SrF分子样品，其密度为2.5×10 cm，相空间密度为6×10 ，两者均比之前的工作提高了4倍。在不同的实验条件下，我们观察到最多可俘获10 个分子，比之前的工作提高了5倍。最后，通过降低所施加俘获光的强度，我们观察到分子温度低至250 μK。
