title: Spin-polarized surface resonances accompanying topological surface state formation.
abstract: 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.
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Jozwiak
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.|Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.|Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Sobota
authors.affiliation: Graduate Group in Applied Science and Technology, University of California, Berkeley, California 94720, USA.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Gotlieb
authors.affiliation: Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, USA.|Computational Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Alexander F
authors.identifier: 0000-0002-5426-5181
authors.initials: AF
authors.lastname: Kemper
authors.affiliation: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.
authors.forename: Costel R
authors.initials: CR
authors.lastname: Rotundu
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.|Department of Physics, University of California, Berkeley, California 94720, USA.|Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Birgeneau
authors.affiliation: Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Zahid
authors.initials: Z
authors.lastname: Hussain
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.|Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: Dung-Hai
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.|Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University, Stanford, CA 94305, USA.
authors.forename: Zhi-Xun
authors.initials: ZX
authors.lastname: Shen
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.|Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Lanzara