Hydrodynamics with spacetime-dependent scattering length
Hydrodynamics with spacetime-dependent scattering length
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DOI：
10.1103/physreva.98.063634
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发表时间：
2018-12-26
影响因子：
2.9
通讯作者：
Nishida, Yusuke
中科院分区：
文献类型：
--
作者：
Fujii, Keisuke;Nishida, Yusuke
流体动力学提供了一个简明而有力的描述，描述了热力学平衡之外的相关系统的长时间和长距离物理学。在这里，我们构建非相对论粒子的流体动力学方程与时空相关的散射长度，并表明它进入本构关系唯一，以代表流体的膨胀和收缩在正常和超流相。因此，我们发现，由于时空相关的散射长度的接触密度的主要耗散校正是成比例的体积粘度（zeta（2）在超流相）。此外，当散射长度随时间缓慢变化的均匀系统中，熵密度被发现，即使没有流体流动的体积粘度成比例，这可能是有用的作为一种新的探针，以测量超冷原子实验中的体积粘度。
Hydrodynamics provides a concise but powerful description of long-time and long-distance physics of correlated systems out of thermodynamic equilibrium. Here we construct hydrodynamic equations for nonrelativistic particles with a spacetime-dependent scattering length and show that it enters constitutive relations uniquely so as to represent the fluid expansion and contraction in both normal and superfluid phases. As a consequence, we find that a leading dissipative correction to the contact density due to the spacetime-dependent scattering length is proportional to the bulk viscosity (zeta(2) in the superfluid phase). Also, when the scattering length is slowly varied over time in a uniform system, the entropy density is found to be produced even without fluid flows in proportion to the bulk viscosity, which may be useful as a novel probe to measure the bulk viscosity in ultracold-atom experiments.