link to homepage

Peter Grünberg Institute

Navigation and service

Dual topological insulator properties detected in Bi1Te1

Jülich, 29. May 2017 – In collaboration with PGI-1, PGI-5, and PGI-6, PGI-9 has demonstrated that stoichiometric Bi1Te1 is a dual 3D topological insulator where a weak topological insulator phase and topological crystalline insulator phase appear simultaneously.

oThe Bi1Te1 thin films were grown by molecular beam epitaxy, and evidence for its dual topological character was found by spin- and angle-resolved photoemission spectroscopy. In particular, the weak topological insulator behavior was proven by the absence of spin-polarized surface states at the 'dark' (0001) surface, whereas the topological crystalline insulator was evidenced by mirror symmetry-protected band crossings at non- time reversal invariant momenta points in the reciprocal space. The experimental results were confirmed by DFT calculations. 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 a magnetic field on one surface and by strain on another surface.

Bi1Te1Topological States in Bi1Te1
Copyright: Forschungszentrum Jülich

Original Publication

M. Eschbach at. al., Bi1Te1 is a dual topological insulator, Nature Communications 8, 14976 (2017), doi:10.1038/ncomms14976


Dr. Gregor Mussler
Peter Grünberg Institute, Semiconductor-Nanoelectronics (PGI-9)
Telefon: +49 2461 61-3580