2016/09/07 by Chris Jozwiak, Jonathan A. Sobota, Kenneth Gotlieb +7 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.1038/ncomms13143
published as Nat. Commun. 7, 13143 (2016)
arxiv created 2016/09/07 · arxiv updated 2016/10/18
Topological insulators host spin-polarized surface states born out of the energetic inversion of bulk bands driven by the spin-orbit interaction. Here we discover previously unidentified consequences of band-inversion on the surface electronic structure of the topological insulator Bi2Se3. By performing simultaneous spin, time, and angle-resolved photoemission spectroscopy, we map the spin-polarized unoccupied electronic structure and identify a surface resonance which is distinct from the topological surface state, yet shares a similar spin- orbital texture with opposite orientation. Its momentum- dependence and spin texture imply an intimate connection with the topological surface state. Calculations show these two distinct states can emerge from trivial Rashba-like states that change topology through the spin-orbit-induced band inversion. This work thus provides a compelling view of the coevolution of surface states through a topological phase transition, enabled by the unique capability of directly measuring the spin-polarized unoccupied band structure.