FisMat2017 - Submission - View

Abstract's title: Edge state reconstruction from strong correlations in quantum spin Hall insulators
Submitting author: Giorgio Sangiovanni
Affiliation: University of Wuerzburg
Affiliation Address: Institut fuer Theoretische Physik und Astrophysik Universitaet Wuerzburg Am Hubland 97074 Wuerzburg - Germany
Country: Germany
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Adriano Amaricci (SISSA, Trieste), Lorenzo Privitera (SISSA, Trieste), F. Petocchi (SISSA, Trieste), M. Capone (SISSA, Trieste), Jan Carl Budich (Gothenburg, Sweden) B. Trauzettel (Wuerzburg, Germany)
Abstract

Many-body effects arising from the Coulomb interaction can force us to revisit the standard description of quantum spin Hall insulators based on non-interacting electrons. In this talk I am going to study a Bernevig-Hughes-Zhang (BHZ) model supplemented by a two-orbital Hubbard term using dynamical mean field theory (DMFT). This is done for a system in the presence of boundaries and the focus is on the fate of the helical edge states.
I will first show the different influence of the  Coulomb repulsion on the bulk and the edge states. Then I will focus on the discovery of an edge reconstruction driven by electronic correlations. The reason is that the helical edge states experience Mott localization for an interaction strength smaller than the bulk one. I will argue that the significance of this edge reconstruction can be understood by topological properties of the system characterized by a local Chern marker.

References:

[1] A. Amaricci, J. C. Budich, M. Capone, B. Trauzettel and G. Sangiovanni.
    First-Order Character and Observable Signatures of Topological Quantum Phase Transitions.
    Phys. Rev. Lett. 114, 185701 (2015).
[2] A. Amaricci, J. C. Budich, M. Capone, B. Trauzettel and G. Sangiovanni.
    Strong correlation effects on topological quantum phase transitions in three dimensions.
    Phys. Rev. B 93, 235112 (2016).
[3] A. Amaricci, L. Privitera, F. Petocchi, M. Capone, G. Sangiovanni and B. Trauzettel.
    Edge states reconstruction from strong correlations in quantum spin Hall insulators.
    Phys. Rev. B 95, 205120 (2017).