Dresden 2011 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 38: Poster Session Transport

TT 38.38: Poster

Mittwoch, 16. März 2011, 14:00–18:00, P3

Surface quantum criticality in topological insulators — •Matthias Sitte, Lars Fritz, and Achim Rosch — Institut für Theoretische Physik, Universität zu Köln, Zülpicher Str. 77, D-50937 Köln

The discovery of graphene has allowed to experimentally study a (2+1)-dimensional variant of quantum electrodynamics. It is known that a phase transition to a gapped phase with broken chiral symmetry can in principle be driven by varying the fine structure constant α. However, in graphene the tunability of α is quite limited. Recently, the surfaces of 3D topological insulators have shown to host states that are also described by massless relativistic Dirac fermions in 2+1 dimensions. In this work we study the tunability of α in materials such as HgTe and CdTe by driving the bulk towards its quantum critical point. We investigate under which conditions chiral symmetry breaking on the surface can be expected.