报告题目：Nonequilibrium electron-phonon coupling: dynamical manipulation of quantum matter

主讲嘉宾：王亚娴（中国科学院物理研究所，副研究员）

活动时间：9月3日（周二）上午10:00 

活动地点：师昌绪楼408会议室

报告简介：

Electron-phonon interaction is an old yet evergreen problem in condensed matter physics. It is closely related to many quantum states we are concerned with, such as superconductivity, charge density waves, and polarons. It also profoundly affects, or often accompanies, critical phenomena such as the formation of excitonic insulators and metal-insulator transitions. An ultrafast laser pulse can reshape the potential energy surface and thus the coupling in the excited states, and may open up a new avenue of ultrafast coherent control of quantum phases and topological orders. However, theoretical approaches often fail to capture the coupled dynamics of the non-thermal excited carriers and the nonequilibrium lattice order.

In this talk, I will introduce how light-induced coherent phonons can cause a quasi-static lattice distortion and result in a Lifshitz transition in a nodal-line semimetal. We also demonstrate how the laser energy can shift the quasi-equilibrium lattice structure towards opposite directions, thus engineering the electronic structure via different regimes. Moreover, I will discuss our recent discovery on how nonequilibrium electron-phonon interaction can interact with the spin degree of freedom, causing ultrafast demagnetization and excitation of chiral phonons in a monolayer ferromagnet. 

嘉宾简介：

王亚娴，2019年在美国俄亥俄州立大学获得博士学位，后在哈佛大学从事博士后研究。2022 年加入中国科学院物理研究所，任副研究员，主要从事非常规输运性质和非平衡态动力学的理论探究。通过发展和应用第一性原理和多尺度模拟计算方法，与实验研究紧密结合，探索量子材料中准粒子动力学的微观机制，预测其输运和响应。近5年来在Nat. Mater.,Nat Phys.,PRL,JACS,Nat. Commun. 等国内外期刊发表论文20余篇，多次受邀在美国物理年会，美国材料研究会年会等学术会议上做特邀报告。

欢迎所内职工和研究生前来交流！