量子电子学报, 2018, 35 (3): 308, 网络出版: 2018-06-09
利用解压缩磁光阱技术实现铷87原子的亚多普勒冷却
Sub-Doppler cooling of87Rb atoms using decompressed magneto-optical trap technique
量子光学 磁光阱 多普勒冷却极限 解压缩磁光阱 偏振梯度冷却 quantum optics magneto-optical trap Doppler cooling limit decompressed magneto-optical trap polarization gradient cooling
摘要
利用解压缩磁光阱(DCMOT)技术将铷87原子温度降低到多普勒冷却极限温度以下。 在磁光阱中获得铷87原子冷原子团,通过减小磁场梯度、降低回泵光功率和增加冷却 光失谐量进一步降低冷原子温度。通过研究原子自由飞行后密度随磁场梯度、回泵光功 率和冷却光失谐量的变化关系,得到最优化的实验参数。测得DCMOT后原子的温度为129 μK, 低于铷87原子的多普勒冷却极限温度(144 μK)。将低温冷原子直接装载到磁阱中,装载效率为25%。
Abstract
Temperature of 87Rb atoms can be cooled below Doppler cooling limit by using the decompressed magneto-optical trap (DCMOT) technique. Cold atoms of 87Rb are trapped in magneto-optical trap (MOT), and the temperature of cold atoms is further lowered by decreasing the magnetic field gradient and repumping light power, increasing the detuning of cooling light. The optimal experimental parameters are obtained by investigating the relationship between atomic density after free flight and the magnetic field gradient, power of repumping light and detuning of cooling light. The atom temperature measured after DCMOT is 129 μK, which is lower than Doppler cooling limit temperature of 87Rb atom (144 μK). The low temperature cold atoms are loaded directly into the magnetic trap with a loading efficiency of 25%.
张东方, 高天佑, 孔令冉, 李凯, 江开军. 利用解压缩磁光阱技术实现铷87原子的亚多普勒冷却[J]. 量子电子学报, 2018, 35(3): 308. ZHANG Dongfang, GAO Tianyou, KONG Lingran, LI Kai, JIANG Kaijun. Sub-Doppler cooling of87Rb atoms using decompressed magneto-optical trap technique[J]. Chinese Journal of Quantum Electronics, 2018, 35(3): 308.