Esfarjani Keivan, Liang Yuan
Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904, USA.
Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22904, USA.
Entropy (Basel). 2022 Nov 1;24(11):1585. doi: 10.3390/e24111585.
In this review, motivated by the recent interest in high-temperature materials, we review our recent progress in theories of lattice dynamics in and out of equilibrium. To investigate thermodynamic properties of anharmonic crystals, the self-consistent phonon theory was developed, mainly in the 1960s, for rare gas atoms and quantum crystals. We have extended this theory to investigate the properties of the equilibrium state of a crystal, including its unit cell shape and size, atomic positions and lattice dynamical properties. Using the equation-of-motion method combined with the fluctuation-dissipation theorem and the Donsker-Furutsu-Novikov (DFN) theorem, this approach was also extended to investigate the non-equilibrium case where there is heat flow across a junction or an interface. The formalism is a classical one and therefore valid at high temperatures.
在本综述中，受近期对高温材料的关注所推动，我们回顾了我们在平衡态和非平衡态晶格动力学理论方面的最新进展。为了研究非谐晶体的热力学性质，自洽声子理论主要在20世纪60年代针对稀有气体原子和量子晶体得以发展。我们扩展了该理论以研究晶体平衡态的性质，包括其晶胞形状和大小、原子位置以及晶格动力学性质。通过将运动方程方法与涨落耗散定理以及东斯科尔 - 古津 - 诺维科夫（DFN）定理相结合，该方法还被扩展用于研究存在热流穿过结或界面的非平衡情况。该形式体系是经典的，因此在高温下有效。
