Zhu ZH, Levy G, Ludbrook B, Veenstra CN, Rosen JA, Comin R, Wong D, Dosanjh P, Ubaldini A, Syers P, Butch NP, Paglione J, Elfimov IS, Damascelli A. Rashba spin-splitting control at the surface of the topological insulator Bi2Se3.
Phys Rev Lett 2011;
107:186405. [PMID:
22107654 DOI:
10.1103/physrevlett.107.186405]
[Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Indexed: 05/31/2023]
Abstract
The electronic structure of Bi(2)Se(3) is studied by angle-resolved photoemission and density functional theory. We show that the instability of the surface electronic properties, observed even in ultrahigh-vacuum conditions, can be overcome via in situ potassium deposition. In addition to accurately setting the carrier concentration, new Rashba-like spin-polarized states are induced, with a tunable, reversible, and highly stable spin splitting. Ab initio slab calculations reveal that these Rashba states are derived from 5-quintuple-layer quantum-well states. While the K-induced potential gradient enhances the spin splitting, this may be present on pristine surfaces due to the symmetry breaking of the vacuum-solid interface.
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