The electronic structure of Bi2Se3 is studied by angle-resolved photoemission and density functional theory. We show that the instability of the surface electronic properties, observed even in ultra-high-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 state are derived from the 5QL quantum-well states. While the K-induced potential gradient enhances the spin splitting, this might be already present for pristine surfaces due to the symmetry breaking of the vacuum-solid interface.
@article{arxiv.1106.0552,
title = {Rashba spin-splitting control at the surface of the topological insulator Bi2Se3},
author = {Z. -H. Zhu and G. Levy and B. Ludbrook and C. N. Veenstra and J. A. Rosen and R. Comin and D. Wong and P. Dosanjh and A. Ubaldini and P. Syers and N. P. Butch and J. Paglione and I. S. Elfimov and A. Damascelli},
journal= {arXiv preprint arXiv:1106.0552},
year = {2015}
}
Comments
A high-resolution version can be found at http://www.physics.ubc.ca/~quantmat/ARPES/PUBLICATIONS/Articles/BiSe_K.pdf