## Abstract

The phase structure of two-dimensional topological insulators under a sufficiently strong electron-electron interaction is investigated. The effective theory is constructed by extending the idea of the Kane-Melé model on the graphenelike honeycomb lattice, in terms of U(1) lattice gauge theory (quantum electrodynamics). We analyze the phase structure by the techniques of strong-coupling expansion of lattice gauge theory. As a result, we find that the topological phase structure of the system is modified by the electron-electron interaction. There evolves a new phase with the antiferromagnetism not parallel to the direction pointed by the spin-orbit coupling, in-between the conventional and the topological insulator phases. We also discuss the physical implication of the new phase structure found here, in analogy to the parity-broken phase in lattice quantum chromodynamics, known as the "Aoki phase."

Original language | English |
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Article number | 205440 |

Journal | Physical Review B - Condensed Matter and Materials Physics |

Volume | 87 |

Issue number | 20 |

DOIs | |

Publication status | Published - 2013 May 29 |

## ASJC Scopus subject areas

- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics