2D spontaneous valley polarization from inversion symmetric single-layer lattices  

作　　者：Ting Zhang Xilong Xu Baibiao Huang Ying Dai Yandong Ma 

机构地区：[1]School of Physics,State Key Laboratory of Crystal Materials,Shandong University,Shandanan Street 27,Jinan,250100,China

出　　处：《npj Computational Materials》2022年第1期617-623,共7页计算材料学（英文）

基　　金：This work is supported by the National Natural Science Foundation of China(No.12074217);Shandong Provincial Natural Science Foundation(Nos.ZR2019QA011 and ZR2019MEM013);Shandong Provincial Key Research and Development Program(Major Scientific and Technological Innovation Project)(No.2019JZZY010302);Shandong Provincial Key Research and Development Program(No.2019RKE27004);Shandong Provincial Science Foundation for Excellent Young Scholars(No.ZR2020YQ04);Qilu Young Scholar Program of Shandong University,and Taishan Scholar Program of Shandong Province.

摘　　要：2D spontaneous valley polarization attracts great interest both for its fundamental physics and for its potential applications in advanced information technology,but it can only be obtained from inversion asymmetric single-layer crystals,while the possibility to create 2D spontaneous valley polarization from inversion symmetric single-layer lattices remains unknown.Here,starting from inversion symmetric single-layer lattices,a general design principle for realizing 2D spontaneous valley polarization based on van der Waals interaction is mapped out.Using first-principles calculations,we further demonstrate the feasibility of this design principle in a real material of T-FeCl2.More remarkably,such design principle exhibits the additional exotic out-of-plane ferroelectricity,which could manifest many distinctive properties,for example,ferroelectricity-valley coupling and magnetoelectric coupling.The explored design-guideline and phenomena are applicable to a vast family of 2D materials.Our work not only opens up a platform for 2D valleytronic research but also promises the fundamental research of coupling physics in 2D lattices.

关 键 词：materials SYMMETRIC LATTICES 

分 类 号：O57[理学—粒子物理与原子核物理]