Electric tuning of the surface and quantum well states in Bi2Se3 films: a first-principles study

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Journal of Physics: Condensed Matter

OSTI ID:1159502

Yang, Hong ^[1]; Peng, Xiangyang ^[1]; Liu, Wenliang ^[1]; Wei, Xiaolin ^[1]; Hao, Guolin ^[1]; He, Chaoyu ^[1]; Li, Jin ^[1]; Stocks, George Malcolm ^[2]; Zhong, Jianxin ^[1]

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1. Xiangtan University, Xiangtan Hunan, China
2. ORNL

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.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1159502
• Journal Information: Journal of Physics: Condensed Matter, Vol. 26
• Country of Publication: United States
• Language: English