论文标题
关于周期系统的热电流的定义及其对固体热导率的模拟的影响
On the definition of heat current for periodic systems and its implications for simulations of thermal conductivity in solids
论文作者
论文摘要
我们对经典边界条件的经典系统的热电流进行重新启发，并表明可以将其写入两个术语的总和。第一项是系统能量密度第一刻的时间导数，而第二项通过通过周期边界的能量传输速率表示。我们表明，在固体中，单独的第二项会导致与在绿色kubo进近中使用的热电流的完整表达相同的热导率。更普遍的是，虽然通过翻译原始周期边界形成的任何表面传递的能量都可以用于计算导热率。这些陈述已针对两个系统进行验证：晶粒氩和氩和K形成界面的晶体。
We re-derive the expression for the heat current for a classical system subject to periodic boundary conditions and show that it can be written as a sum of two terms. The first term is a time derivative of the first moment of the system energy density while the second term is expressed through the energy transfer rate through the periodic boundary. We show that in solids the second term alone leads to the same thermal conductivity as the full expression for the heat current when used in the Green-Kubo approach. More generally, energy passing though any surface formed by translation of the original periodic boundary can be used to calculate thermal conductivity. These statements are verified for two systems: crystalline argon and crystals of argon and krypton forming an interface.
