G. Bihlmayer, Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
Edge states of topological insulators (TIs) provide a wealth of fascinating
properties, e.g. spin-momentum locking and robustness against perturbations
that do not break time-reversal symmetry. Density functional theory provides
a unique tool to describe not only the bulk phases of TIs, but also their
boundaries that carry these states and investigate their response to
different boundary conditions, like interfaces, adatoms or local structural
modifications.
I will present examples of two-dimensional TIs, like the structurally
fragile Bi bilayer [1] that can be stabilized on a Bi2Te3 substrate [2].
This material is itself a three-dimensional topological insulator where the
edge state is modified at the interface to the Bi layer. Furthermore,
enhancement of spin-orbit coupling in supported graphene, the first
theoretically proposed TI, and edge states on nanoribbons are shown.
Comparison to experimental evidence, where available, confirms the
theoretical predictions.
[1] M.Wada, S.Murakami, F.Freimuth, and G.Bihlmayer,
Phys. Rev. B 83, 121310(R) (2011).
[2] T.Hirahara, G.Bihlmayer, Y.Sakamoto, M.Yamada, H.Miyazaki, S-i.Kimura,
S.Blügel, and S.Hasegawa, Phys.Rev.Lett. 107, 166801 (2011).