Regensburg 2019 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 3: Topological Insulators (joint session TT/MA)
TT 3.12: Vortrag
Montag, 1. April 2019, 12:30–12:45, Theater
Topological edge states in novel monolayer 2D materials — •Luca Vannucci1, Nicola Marzari2, and Kristian S. Thygesen1 — 1CAMD, Technical University of Denmark, 2800 Kongens Lyngby, Denmark — 2THEOS, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
We discuss topologically protected metallic edge states emerging at the boundary of novel two-dimensional (2D) materials. With input from newly developed computational 2D materials databases [1,2], containing thousands of 2D materials and forming the ideal starting point for the investigation of unexplored topological materials, we focus on new interesting candidates to achieve large-gap quantum spin Hall insulators [3]. We then explore the electronic band structure of such candidates in different nanoribbon geometries, highlighting the emergence of robust metallic states whose eigenvalues cross the region of bulk gap. Such states are manifestly localized at the edge of the ribbon, with a localization length linked to the direct bulk gap, and show all typical signatures of topological edge modes protected by time-reversal symmetry.
[1] N. Mounet et al., Nat Nanotechnol. 13, 246 (2018)
[2] S. Haastrup et al., 2D Mater. 5, 042002 (2018)
[3] A. Marrazzo et al., Phys. Rev. Lett. 120, 117701 (2018);