论文标题
在淬灭的随机电势中，改进的现场理论方法可用于非互动的布朗颗粒
Improved field theoretical approach to noninteracting Brownian particles in a quenched random potential
论文作者
论文摘要
在存在淬灭的高斯随机电位的情况下，我们构建了一种动态场理论，用于非互动的布朗颗粒。场理论的主要变量是密度波动，它可以测量局部密度及其平均值之间的差异。对于赋予随机电位的实现，平均密度在空间上是不均匀的。仅在平均疾病构型上平均后才变得均匀。我们为密度相关函数开发了示意性扰动理论，并通过求和所有有助于它的图表来精确地计算响应函数的零频率成分。从这个确切的结果和保持平衡动力学的波动耗散关系，我们发现连接的密度相关函数始终在所有无序强度值的长期限制中始终衰减至零，这表明该系统始终保持成真。这种非扰动计算取决于本场理论方案的简单图表结构。我们将我们的示意性扰动理论与最近的论文[B. \ Kim，M。\ Fuchs和V. \ Krakoviack，J. \ Stat。\ Mech。\（2020）023301]进行了详细比较，该理论使用了均匀平均值周围的密度波动，并讨论了两种形式的形式的差异。
We construct a dynamical field theory for noninteracting Brownian particles in the presence of a quenched Gaussian random potential. The main variable for the field theory is the density fluctuation which measures the difference between the local density and its average value. The average density is spatially inhomogeneous for given realization of the random potential. It becomes uniform only after averaged over the disorder configurations. We develop the diagrammatic perturbation theory for the density correlation function and calculate the zero-frequency component of the response function exactly by summing all the diagrams contributing to it. From this exact result and the fluctuation dissipation relation, which holds in an equilibrium dynamics, we find that the connected density correlation function always decays to zero in the long-time limit for all values of disorder strength implying that the system always remains ergodic. This nonperturbative calculation relies on the simple diagrammatic structure of the present field theoretical scheme. We compare in detail our diagrammatic perturbation theory with the one used in a recent paper [B.\ Kim, M.\ Fuchs and V.\ Krakoviack, J.\ Stat.\ Mech.\ (2020) 023301], which uses the density fluctuation around the uniform average, and discuss the difference in the diagrammatic structures of the two formulations.
