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arXiv · 1609.01842

Spin-Polarized Surface Resonances Accompanying Topological Surface State Formation

Chris Jozwiak·Jonathan A. Sobota·Kenneth Gotlieb·Alexander F. Kemper·Costel R. Rotundu·Robert J. Birgeneau·Zahid Hussain·Dung-Hai Lee·Zhi-Xun Shen·Alessandra Lanzara
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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 Bi$_2$Se$_3$. 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.

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Chris Jozwiak, Jonathan A. Sobota, Kenneth Gotlieb, Alexander F. Kemper, Costel R. Rotundu, Robert J. Birgeneau, Zahid Hussain, Dung-Hai Lee, Zhi-Xun Shen, Alessandra Lanzara. 2016-09-07. Spin-Polarized Surface Resonances Accompanying Topological Surface State Formation. https://doi.org/10.1038/ncomms13143

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