Year: 2016
Type: article
Abstract: We investigate the role of short-ranged electron-electron interactions in a paradigmatic model of three-dimensional topological insulators, using dynamical mean-field theory and focusing on nonmagnetically ordered solutions. The noninteracting band structure is controlled by a mass term $M$, whose value discriminates between three different insulating phases, a trivial band insulator and two distinct topologically nontrivial phases. We characterize the evolution of the transitions between the different phases as a function of the local Coulomb repulsion $U$ and find a remarkable dependence of the $U\ensuremath{-}M$ phase diagram on the value of the local Hund's exchange coupling $J$. However, regardless of the value of $J$, following the evolution of the topological transition line between a trivial band insulator and a topological insulator, we find a critical value of $U$ separating a continuous transition from a first-order one. When the Hund's coupling is significant, a Mott insulator is stabilized at large $U$. In proximity of the Mott transition we observe the emergence of an anomalous ``Mott-like'' strong topological insulator state.
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G2158694287, G3781121477, G4117425174
OpenAlex ID: W2302003277