发表机构
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences; School of Physical Sciences, University of Chinese Academy of Sciences; Songshan Lake Materials Laboratory（中国科学院物理研究所凝聚态物理国家实验室; 中国科学院大学物理科学学院; 松山湖材料实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文开发了EMLMD框架，通过电子信息校准实现高精度光激发材料动态模拟，揭示了铋光相变的声子竞争与硒光非晶化的微观动力学，为相关研究提供了通用范式。
AI 中文摘要
电子激发后的非绝热耦合电子-核动力学是材料中多种光诱导功能现象的微观机制及合理调控的基础，但直接的第一性原理模拟计算成本极高。本文开发了非绝热激发态机器学习分子动力学（EMLMD）模拟框架，其中光激发后的非平衡电子信息（如电子温度）通过高精度实时时间依赖密度泛函理论（rt-TDDFT）基准模拟进行严格校准，可准确重构激发态势能面（PES）。该框架天然包含激发态电子-声子耦合，且能内在捕捉光诱导声子非谐性，这两者均是标准机器学习分子动力学所缺失的，因此能为激发态原子演化提供第一性原理级别的精度。大规模EMLMD模拟解析了光激发材料中时间与动量分辨的声子动力学，直接揭示了铋的光诱导相变过程中光生相干声子与热声子的竞争关系；同时还解析了硒光非晶化过程中难以捉摸的原子级微观动力学与全局结构重排。在平衡精度与效率的前提下，EMLMD为解决复杂激发态分子动力学研究中的关键挑战提供了通用范式。
英文摘要
Nonadiabatic coupled electron-nuclear dynamics upon electronic excitation underpin the microscopic mechanism and rational modulation of diverse photoinduced functional phenomena in materials, yet their direct first-principles simulations remain computationally demanding. Here we develop a framework for nonadiabatic excited-state machine-learning molecular dynamics (EMLMD) simulations, where the nonequilibrium electronic information upon photoexcitation such as electron temperature is rigorously calibrated from high-precision real-time time-dependent density functional theory (rt-TDDFT) benchmark simulations, enabling accurate reconstruction of excited-state potential energy surfaces (PES). This framework natively incorporates the excited-state electron-phonon couplings and intrinsically captures photoinduced phonon anharmonicity, both of which are missing in standard machine learning molecular dynamics, thus delivering first-principles-level accuracy for excited-state atomic evolutions. Large-scale EMLMD simulations resolve time- and momentum-resolved phonon dynamics in photoexcited materials, directly uncovering the competition between photogenerated coherent phonons and thermal phonons during photoinduced phase transition of bismuth. It also simultaneously resolves elusive atomic-scale microscopic dynamics and global structural rearrangement for selenium photoamorphization. Balancing high accuracy and efficiency, EMLMD offers a versatile paradigm to tackle key challenges in the study of complex excited-state molecular dynamics.
Comments11 pages, 4 figures, 1 table
