We find a state characterized by a spontaneous loop-spin current and a single-particle gap in the Hubbard model within the variational cluster approach. This state exists for arbitrarily small interaction in a half-filled honeycomb lattice. Moreover, from the calculations of the topological invariants for the interacting system, it is shown that this gapped state has nontrivial topological characters; this state is the topological Mott insulating state. This result implies the ubiquity of topological Mott insulating phases.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2014 Aug 4|
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials