量子电子学报, 2016, 33 (4): 456, 网络出版: 2016-10-24
相变温度以上超冷玻色气体的一阶空间相干性
First-order spatial coherence of ultracold Bose gas above phase transition temperature
量子光学 一阶空间相干性 对比度 相变温度 quantum optics first-order spatial coherence contrast phase transition temperature
摘要
利用一维光学驻波场产生的相位光栅对静磁阱中相变温度以上超冷原子气体的一阶相干性质进行研究。 理论计算了热原子的干涉图样,实验获得了相变温度以上超冷原子气体的干涉图样。通过比较理论和实验原 子气体干涉图样的对比度发现:当超冷原子气体温度非常接近相变温度时,原子气体的相干性明显好于热 原子的相干性;随着温度的升高,原子气体的相干性逐渐减弱,最终与热原子的相干性完全相同。
Abstract
The first-order spatial coherence of ultracold Bose gas above the phase transition temperature in static-magnetic trap is investigated by using phase grating produced by one dimensional optical standing wave field. The interference patterns of thermal atoms are calculated in theory, and the interference patterns of ultracold atomic gas above the phase transition temperature are also obtained by experiments. By comparing the contrast of interference patterns of atomic gas in theory and experiment, it’s found that when the temperature of ultracold atomic gas is very close to the phase transition temperature, coherence of the atomic gas is better than that of thermal atom. With increasing of temperature, the coherence of atomic gas decreases gradually, and it is the same as that of thermal atom finally.
孙超, 王兵, 朱强, 熊德智. 相变温度以上超冷玻色气体的一阶空间相干性[J]. 量子电子学报, 2016, 33(4): 456. SUN Chao, WANG Bing, ZHU Qiang, XIONG Dezhi. First-order spatial coherence of ultracold Bose gas above phase transition temperature[J]. Chinese Journal of Quantum Electronics, 2016, 33(4): 456.