Wang Yu-Chen, Zhao Yi
State Key Laboratory of Physical Chemistry of Solid Surfaces, iCHEM, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China.
J Chem Phys. 2022 May 28;156(20):204116. doi: 10.1063/5.0091124.
A new diagrammatic quantum Monte Carlo approach is proposed to deal with the imaginary time propagator involving both dynamic disorder (i.e., electron-phonon interactions) and static disorder of local or nonlocal nature in a unified and numerically exact way. The establishment of the whole framework relies on a general reciprocal-space expression and a generalized Wick's theorem for the static disorder. Since the numerical cost is independent of the system size, various physical quantities, such as the thermally averaged coherence, Matsubara one-particle Green's function, and current autocorrelation function, can be efficiently evaluated in the thermodynamic limit (infinite in the system size). The validity and performance of the proposed approach are systematically examined in a broad parameter regime. This approach, combined with proper numerical analytic continuation methods and first-principles calculations, is expected to be a versatile tool toward the calculation of various transport properties, such as mobilities in realistic semiconductors involving multiple electronic energy bands, high-frequency optical and low-frequency acoustic phonons, different forms of dynamic and static disorders, and anisotropy.
提出了一种新的图解量子蒙特卡罗方法，以统一且数值精确的方式处理涉及动态无序（即电子 - 声子相互作用）以及局部或非局部性质的静态无序的虚时传播子。整个框架的建立依赖于一个通用的倒易空间表达式和一个针对静态无序的广义维克定理。由于数值成本与系统大小无关，在热力学极限（系统大小为无穷大）下，可以有效地评估各种物理量，如热平均相干性、松原单粒子格林函数和电流自相关函数。在广泛的参数范围内系统地检验了所提出方法的有效性和性能。这种方法与适当的数值解析延拓方法和第一性原理计算相结合，有望成为计算各种输运性质的通用工具，例如涉及多个电子能带、高频光学和低频声学声子、不同形式的动态和静态无序以及各向异性的实际半导体中的迁移率。
