title: Electric tuning of the surface and quantum well states in Bi2Se3 films: a first-principles study.
abstract: Based on first-principles calculations in the framework of van der Waals density functional theory, we find that giant, Rashba-like spin splittings can be induced in both the surface states and quantum well states of thin Bi2Se3 films by application of an external electric field. The charge is redistributed so that the Dirac cones of the upper and lower surfaces become nondegenerate and completely gapless. Interestingly, a momentum-dependent spin texture is developed on the two surfaces of the films. Some of the quantum well states, which reside in the middle of the Bi2Se3 film under zero field, are driven to the surface by the electric field. The Rashba splitting energy has a highly non-linear dependence on the momentum and the electric field due to the large contribution of the high-order Rashba terms, which suggests complex spin dynamics in the thin films of Bi2Se3 under an electric field.
authors.affiliation: Hunan Key Laboratory of Micro-Nano Energy Materials and Devices, Xiangtan University, Hunan 411105, People's Republic of China. Laboratory for Quantum Engineering and Micro-Nano Energy Technology and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan 411105, People's Republic of China. Department of Physics, Jishou University, Hunan 416000, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Peng
authors.forename: Wenliang
authors.initials: W
authors.lastname: Liu
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Wei
authors.forename: Guolin
authors.initials: G
authors.lastname: Hao
authors.forename: Chaoyu
authors.initials: C
authors.lastname: He
authors.forename: Jin
authors.initials: J
authors.lastname: Li
authors.forename: G Malcolm
authors.initials: GM
authors.lastname: Stocks
authors.forename: Jianxin
authors.initials: J
authors.lastname: Zhong