Effect of disorder close to the superfluid transition in a two-dimensional Bose gas
Effect of disorder close to the superfluid transition in a two-dimensional Bose gas
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二维玻色气体中接近超流转变的无序效应
DOI：
10.1103/physreva.85.033602
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发表时间：
2011
影响因子：
2.9
通讯作者：
T. Bourdel
中科院分区：
文献类型：
--
作者：
B. Allard;T. Plisson;M. Holzmann;G. Salomon;A. Aspect;P. Bouyer;T. Bourdel
实验研究了无序对准二维（2D）~（87）Rb云Berezinskiii-Kosterlitz-BKT相变附近的影响。无序相关长度是玻色气体特征长度尺度（热布罗意波长，愈合长度）的顺序，从而在微观水平上修改的物理紊乱。我们分析的云的相干性，通过测量的动量分布，两个无序的强度，作为其简并度的函数。对于中度无序，相干的出现仍然陡峭，但转移到一个较低的熵。相反，对于强无序，相干性的增长受到阻碍。我们的研究是一个实验实现的脏玻色子问题，在一个良好的控制原子系统，适用于定量分析。
We experimentally study the effect of disorder on trapped quasi two-dimensional (2D) 87Rb clouds in the vicinity of the Berezinskii-Kosterlitz-Thouless (BKT) phase transition. The disorder correlation length is of the order of the Bose gas characteristic length scales (thermal de Broglie wavelength, healing length) and disorder thus modifies the physics at a microscopic level. We analyze the coherence properties of the cloud through measurements of the momentum distributions, for two disorder strengths, as a function of its degeneracy. For moderate disorder, the emergence of coherence remains steep but is shifted to a lower entropy. In contrast, for strong disorder, the growth of coherence is hindered. Our study is an experimental realization of the dirty boson problem in a well controlled atomic system suitable for quantitative analysis.