二维 NX（N = 镓、铟；X = 硫、硒、碲）单层中 Rashba 自旋分裂的电场控制

Electric field control of Rashba spin splitting in 2D NX (N = Ga, In; X = S, Se, Te) monolayer.

作者信息

Ju Weiwei, Wang Donghui, Li Tongwei, Wang Hui, Zhou Qingxiao, Xu Yanmin, Li Haisheng, Gong Shijing

机构信息

College of Physics and Engineering and Henan Key Laboratory of Photoelectric Energy Storage Materials and Applications, Henan University of Science and Technology, Luoyang 471023, People's Republic of China. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, People's Republic of China.

出版信息

J Phys Condens Matter. 2020 Apr 24;32(17):175503. doi: 10.1088/1361-648X/ab6b88.

DOI:10.1088/1361-648X/ab6b88

PMID:31935706

Abstract

Spin splitting of the nonmagnetic two dimensional (2D) layered NX (N = Ga, In; X = S, Se, Te) monolayer is investigated based on the density functional theory. Due to the mirror symmetry, there is no Rashba spin splitting (RSS) in the freestanding NX plane. It is found that applying the external electric field perpendicular to the NX plane can result in sizable RSS around the Γ point due to the mirror symmetry breaking. The induced RSS is mainly influenced by the anions X and gradually strengthens with the increase of external electric field. The considerable RSS is observed in NTe systems. Moreover, the influence of in-plane biaxial strain on RSS is explored, and the tensile strain can enhance the RSS, especially for those bands around the Fermi level. Our theoretical investigation provides a deep insight in spin splitting behaviors in NX monolayers and agrees well with the experimental report.

摘要

基于密度泛函理论研究了非磁性二维（2D）层状NX（N = Ga、In；X = S、Se、Te）单层的自旋分裂。由于镜面对称性，独立的NX平面中不存在Rashba自旋分裂（RSS）。研究发现，施加垂直于NX平面的外部电场会由于镜面对称性破缺而在Γ点附近产生可观的RSS。诱导的RSS主要受阴离子X的影响，并随着外部电场的增加而逐渐增强。在NTe体系中观察到了可观的RSS。此外，还探讨了面内双轴应变对RSS的影响，拉伸应变可以增强RSS，特别是对于费米能级附近的那些能带。我们的理论研究深入洞察了NX单层中的自旋分裂行为，与实验报告吻合良好。