Nature of spin-lattice coupling in two-dimensional CrI3 and CrGeTe3

作     者：Jing Li JunSheng Feng PanShuo Wang ErJun Kan HongJun Xiang Jing Li;JunSheng Feng;PanShuo Wang;ErJun Kan;HongJun Xiang

作者机构：Key Laboratory of Computational Physical Sciences (Ministry of Education) State Key Laboratory of Surface Physicsand Department of Physics Fudan University Shanghai Qi Zhi Institute School of Physics and Materials Engineering Hefei Normal University Department of Applied Physics and Institution of Energy and Microstructure Nanjing University of Science and Technology Collaborative Innovation Center of Advanced Microstructures 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学:物理学 力学 天文学(英文版))

年 卷 期：2021年第64卷第8期

页      面：67-75页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 11825403, and 11804138) the Program for Professor of Special Appointment (Eastern Scholar) supported by Anhui Provincial Natural Science Foundation (Grant No.1908085MA10) the Opening Foundation of State Key Laboratory of Surface Physics Fudan University (Grant No. KF2019＿07) 

主　　题：spin-lattice effect two-dimensional magnetic materials first-principle calculation 

摘      要：Spin-lattice (SL) coupling plays an important role in spintronic applications given its effects on magnetic,ferroelectric,optical,and thermodynamic properties.Experiments and theoretical calculations have revealed a large SL coupling effect in CrGeTe3and CrI3monolayers.However,the microscopic origin of SL coupling in these systems is still unclear.In this work,we develop a systematic method to explore the atomistic mechanism of SL coupling based on the density functional theory.We find that the first-and second-order SL couplings in ternary system CrGeTe3are considerably stronger than those in binary system CrI3.For the first-order SL coupling,the Cr ions of the magnetic pair and Ge ions positively contribute to the strain enhancement of ferromagnetism in CrGeTe3.However,the Cr ions provide a negative contribution in CrI3.Furthermore,our tight-binding analysis suggests that the p-d hopping in CrGeTe3gradually decreases with the tensile strain,rapidly enhancing the ferromagnetism under the tensile strain.The large frequency shifts in CrGeTe3are caused by the large second-order exchange derivatives (one type of second-order SL coupling) of the Cr ions of the magnetic pair.