物理学院学术报告（第47期）

报告题目：Ferroelectric hafnia: a new era for ferroelectric physics

报告专家：刘仕研究员    西湖大学物理系

报告时间：2024年07月09日（周二）15:00

报告地点：理6栋320      邀请人：赵锦柱

报告内容：

The discovery of ferroelectricity in fluorite-structured HfO2 has revolutionized our understanding of ferroelectric materials, traditionally dominated by studies on perovskite oxides. This silicon-compatible ferroelectric holds the promise of implementing ferroelectric functionalities into integrated circuits for novel nanoelectronics. In this talk, I will discuss our understanding of ferroelectric HfO2 based on both first-principles modeling and deep-learning-assisted large-scale molecular dynamics. This chemically “simple” binary oxide is rather complex, exhibiting several unique properties distinct from perovskite ferroelectrics. Notable examples are the electric auxetic effect, structural polymorphism coupled to the charge state of the oxygen vacancy, dual-valued remnant polarization, and ultrahigh oxygen ion mobility promoted by bias-driven successive ferroelectric transitions. Recently, with a multiscale approach that incorporates atomistic insights of nucleation and growth at the domain wall, we predict that the theoretical lower limit of the coercive field of HfO2 is unexpectedly low, at 0.1 MV/cm. This counterintuitive  theoretical prediction will serve as a reference point in the development and optimization of hafnia-based ferroelectrics.

专家简介：

刘仕，2009年本科毕业于中国科学技术大学，2015年博士毕业于美国宾夕法尼亚大学，博士后工作于华盛顿卡内基研究所和美国陆军研究所，现为西湖大学理学院物理系特聘研究员、博士生导师。先后入选浙江省和国家海外高层次人才引进计划青年项目。长期从事计算物理和计算材料学方向的研究工作，综合运用第一性原理密度泛函理论计算和大尺度分子动力学，研究功能氧化物和量子材料的构性关系。自2013年以来，共参与发表文章90余篇。目前主持国家科技部重点研发青年科学家项目、国家自然科学基金委重大研究计划培育项目、面上项目、青年科学基金项目等多个项目。