Bi1Te1: A New Dual Topological Insulator
Abstract
We present, a combined theoretical and experimental study on the prediction and verification of the dual topological insulating character of the stoichiometric natural superlattice phase Bi1Te1 = [Bi2]1 [Bi2Te3]2. We identify Bi1Te1 by density functional theory to exhibit a non-trivial time-reversal symmetry-driven character of Z2 = (0; 001) and additionally a mirror-symmetry induced mirror Chern number of vM = -2, which indicates that Bi1Te1 is both a weak topological insulator (WTI) and a topological crystalline insulator (TCI). The coexistence of the two phenomena preordain distinct crystal planes to host topological surface states that are protected by the respective symmetries. We confirm the stacking sequence of our MBE-grown Bi1Te1 thin films by X-ray diffraction and transmission electron microscopy (STEM), and find clear indications of the TCI and WTI character in the surface spin electronic structure by spin- and angle-resolved photoemission spectroscopy.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2017
- Bibcode:
- 2017APS..MAR.R3011P