Light induced space-time patterns in a superfluid Fermi gas
Light induced space-time patterns in a superfluid Fermi gas
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超流费米气体中的光诱导时空模式
DOI：
10.1007/s11433-021-1718-1
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Wu Haibin
中科院分区：
文献类型：
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作者：
Li Fang;Deng Shujin;Zhang Liang;Xia Jiahui;Yi Licheng;Wu Haibin
调制不稳定性导致的斑图是普遍存在的，在光学和玻色-爱因斯坦凝聚中得到了广泛的研究。然而，这些模式还没有实现在超冷费米气体，虽然有相当大的理论兴趣在这一领域。在这里，我们报告的实验观察的时空图案的超流费米气体激发的红失谐激光。纵向空间起伏的激光束诱导两种不同类型的图案的自发形成。对于强相互作用的费米气体，伴随声子激发的诱导图样在频率和波矢之间表现出显著的“X”型色散关系。然后，研究了这种斑图在玻色-爱因斯坦凝聚体中向Bardeen-Cooper-Schrieffer渡越的传播，得到了与声速有关的斑图，并与理论计算结果进行了比较.在非相互作用的费米气体中观察到的图案是静止的，没有声子激发，并显示出更长的寿命。
Patterns resulted from modulation instability are ubiquitous and have been extensively studied in optics and Bose-Einstein condensates. However, these patterns have not been realized in ultracold Fermi gases, although there has been considerable theoretical interest in this field. Here we report an experimental observation of space-time patterns in a superfluid Fermi gas excited by red-detuned laser light. Longitudinal spatially fluctuated laser beams induce the spontaneous formation of two different kinds of patterns. For strongly interacting Fermi gas, the induced patterns accompanied by phonon excitations demonstrate a striking “X”-type dispersion relation between frequency and wavevector. Then, the propagation of such patterns in the Bose-Einstein condensate to Bardeen-Cooper-Schrieffer crossover is investigated, which is related to the speed of sound and agrees well with theoretical calculations. The observed patterns in noninteracting Fermi gases are stationary without phonon excitations and show a much longer lifetime.