文献类型：期刊文献

英文题名：Anisotropy-induced phase transitions in an intrinsic half-Chern insulator Ni2I2

作者：Liu, Lei[1,2,3,4];Huan, Hao[1,2,3,4];Xue, Yang[1,2,3,5];Bao, Hairui[1,2,3,4];Yang, Zhongqin[1,2,3,4]

机构：[1]Fudan Univ, State Key Lab Surface Phys, Shanghai 200433, Peoples R China;[2]Fudan Univ, Key Lab Computat Phys Sci MOE, Shanghai 200433, Peoples R China;[3]Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China;[4]Shanghai Qi Zhi Inst, Shanghai 200030, Peoples R China;[5]East China Univ Sci & Technol, Sch Sci, Shanghai 200237, Peoples R China

年份：2022

卷号：14

期号：36

起止页码：13378

外文期刊名：NANOSCALE

收录：;EI(收录号：20224313010619);WOS:【SCI-EXPANDED(收录号:WOS:000850530800001)】；

基金：This work was supported by the National Natural Science Foundation of China under Grant No. 11874117, 12174059, and 11904101 and the Natural Science Foundation of Shanghai under Grant No. 21ZR1408200. The calculations were performed at the High Performance Computational Center (HPCC) of the Department of Physics at Fudan University.

语种：英文

外文关键词：Calculations - Energy gap - Monolayers - Nickel - Nickel compounds - Spin polarization - Topology

摘要：One crucial target of research on spintronics is to achieve flexibly tunable and highly efficient spin-polarized electronic current. In this work, by using first-principles calculations and topological characterization theories, we propose an intrinsic half-Chern insulator (HCI) in a Ni2I2 monolayer, which possesses 100% spin-polarized topologically nontrivial edge states, distinct from ordinary Chern insulators. Its band gap is formed due to the lifting of the double degeneracy of non-Dirac bands composed of Ni d(xz)/d(yz) orbitals. The HCI becomes a half semiconductor (HS) or a combined state of a half metal (HM) and an HCI if biaxial strain is applied. The phase transition is found to be associated with the unique anisotropy of the bands, originating from the diverse orbital distributions and the opposite moving in energy of Ni d(xy) and d(xz)/d(yz) bands under the strain. Our findings demonstrate that the monolayer Ni2I2 is a unique Chern insulator with ideal spintronic properties, supporting versatile applications in spintronic devices with very high spin polarization and extremely low-power dissipation.