Single-Particle Spectral Density of a Bose Gas in the Two-Fluid Hydrodynamic Regime
Single-Particle Spectral Density of a Bose Gas in the Two-Fluid Hydrodynamic Regime
复制标题
双流体流体动力学状态下玻色气体的单粒子谱密度
DOI：
10.1103/physreva.84.053612
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发表时间：
2011
影响因子：
2.9
通讯作者：
Tetsuro Nikuni Allan Griffin
中科院分区：
文献类型：
--
作者：
Emiko Arahata;Tetsuro Nikuni Allan Griffin
在玻色超流体中，单粒子绿色函数可以直接与流体动力学区域中的超流体速度-速度相关函数相关。单粒子谱密度的显式表达式最初是由霍恩伯格和马丁在1965年从超流体的双流体方程开始写下来的。我们给出一个简单的推导他们的结果。利用这些结果，我们计算的相对权重的第一和第二声模式的单粒子谱密度作为温度的函数在一个均匀的玻色气体。我们表明，第二个声音模式，使一个相对较高的温度区域的单粒子谱的主要贡献。我们还讨论了用光电子能谱实验观测玻色气体中第二声模的可能性。
In Bose superfluids, the single-particle Green's function can be directly related to the superfluid velocity-velocity correlation function in the hydrodynamic regime. An explicit expression for the single-particle spectral density was originally written down by Hohenberg and Martin in 1965, starting from the two-fluid equations for a superfluid. We give a simple derivation of their results. Using these results, we calculate the relative weights of first and second sound modes in the single-particle spectral density as a function of temperature in a uniform Bose gas. We show that the second sound mode makes a dominant contribution to the single-particle spectrum in a relatively high-temperature region. We also discuss the possibility of experimental observation of the second sound mode in a Bose gas by photoemission spectroscopy.