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arXiv 1909.11997cond-mat.quant-gascond-mat.stat-mech
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随机势场中超流体的有效温度

Effective temperature of a superfluid flowing in a random potential

Taiki Haga, Masahito Ueda

摘要:

研究了超流体在弱随机势场中的空间涨落。我们采用经典场论证明了在零温度下的无序平均非平衡二阶关联的序参量是相同的热平均平衡对应的均匀超流体在有效温度。这种等价性背后的物理学原理是,运动凝聚体的无序散射对关联函数的影响与平衡热激发的影响相同。关联函数在一维呈现指数衰减,在二维呈现幂律衰减。我们证明了在超冷原子气体的干涉实验中可以测量有效温度。

英文摘要:

The spatial fluctuations of a superfluid flowing in a weak random potential are investigated. We employ classical field theory to demonstrate that the disorder-averaged nonequilibrium second-order correlation of the order parameter at zero temperature is identical to the thermally averaged equilibrium counterpart of a uniform superfluid at an effective temperature. The physics behind this equivalence is that scattering of a moving condensate by disorder has the same effect on the correlation function as equilibrium thermal excitations. The correlation function exhibits an exponential decay in one dimension and a power-law decay in two dimensions. We show that the effective temperature can be measured in an interference experiment of ultracold atomic gases.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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