美国加州理工学院Marco Bernardi团队近日研究了电子-声子相互作用和极化子的第一原理图解蒙特卡罗。2025年7月10日出版的《自然—物理学》发表了这项成果。
在凝聚态物质中，晶格振动场的声子-量子与电子偶联，导致纠缠电子-声子态的形成，称为极化子。在许多传统和量子材料中常见的中耦合和强耦合体系中，极化子的多体处理需要添加大量的电子-声子费曼图。在这方面，图解蒙特卡罗是一种有效的图解求和方法，并已被用于研究简化电子-声子模型中的极化子。
研究组开发了基于精确的第一性原理电子-声子相互作用的图解蒙特卡罗计算，使实际材料中极化子的基态和动力学性质的数值精确结果成为可能。研究组在LiF， SrTiO3，金红石和锐钛矿TiO2中实现了这些计算，并描述了局域和非局域极化子。他们的工作使电子-声子相互作用和极化子在弱到强耦合状态下的精确建模成为可能。该研究结果将对强电子-声子耦合下的输运现象、线性响应和超导性提供更深入的见解。
附：英文原文
Title: First-principles diagrammatic Monte Carlo for electron–phonon interactions and polaron
Author: Luo, Yao, Park, Jinsoo, Bernardi, Marco
Issue&Volume: 2025-07-10
Abstract: In condensed matter, phonons—quanta of the lattice vibration field—couple with electrons, leading to the formation of entangled electron–phonon states called polarons. In the intermediate- and strong-coupling regimes common to many conventional and quantum materials, a many-body treatment of polarons requires adding up a large number of electron–phonon Feynman diagrams. In this regard, diagrammatic Monte Carlo is an efficient method for diagram summation and has been used to study polarons within simplified electron–phonon models. Here we develop diagrammatic Monte Carlo calculations based on accurate first-principles electron–phonon interactions, enabling numerically exact results for the ground-state and dynamical properties of polarons in real materials. We implement these calculations in LiF, SrTiO3, and rutile and anatase TiO2, and describe both localized and delocalized polarons. Our work enables the precise modeling of electron–phonon interactions and polarons in coupling regimes ranging from weak to strong. The results will provide deeper insights into transport phenomena, linear response and superconductivity within the strong electron–phonon coupling regime.
DOI: 10.1038/s41567-025-02954-1
Source: https://www.nature.com/articles/s41567-025-02954-1