Details

Autor(en) / Beteiligte

• Eschbach, Markus
• Lanius, Martin
• Niu, Chengwang
• Młyńczak, Ewa
• Gospodarič, Pika
• Kellner, Jens
• Schüffelgen, Peter
• Gehlmann, Mathias
• Döring, Sven
• Neumann, Elmar
• Luysberg, Martina
• Mussler, Gregor
• Plucinski, Lukasz
• Morgenstern, Markus
• Grützmacher, Detlev
• Bihlmayer, Gustav
• Blügel, Stefan
• Schneider, Claus M.

Titel

Bi1Te1 is a dual topological insulator

Ist Teil von

• Nature communications, 2017-04, Vol.8 (1), p.14976-14976, Article 14976

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• New three-dimensional (3D) topological phases can emerge in superlattices containing constituents of known two-dimensional topologies. Here we demonstrate that stoichiometric Bi 1 Te 1 , which is a natural superlattice of alternating two Bi 2 Te 3 quintuple layers and one Bi bilayer, is a dual 3D topological insulator where a weak topological insulator phase and topological crystalline insulator phase appear simultaneously. By density functional theory, we find indices (0;001) and a non-zero mirror Chern number. We have synthesized Bi 1 Te 1 by molecular beam epitaxy and found evidence for its topological crystalline and weak topological character by spin- and angle-resolved photoemission spectroscopy. The dual topology opens the possibility to gap the differently protected metallic surface states on different surfaces independently by breaking the respective symmetries, for example, by magnetic field on one surface and by strain on another surface. Coexistence of a topological insulator phase and a topological crystalline insulator phase helps to maintain topological properties under a controlled symmetry breaking perturbation. Here, Eschback et al . report a superlattice of Bi and Bi 2 Te 3 to be such a dual topological insulator.