Topological phase transition based on the attractive Hubbard model. (7th November 2019)

• Record Type: Journal Article
• Authors: Qi, Fenghua; Cao, Jun; Cao, Jie; Li, Xiao; Zhang, Lifa
• Is Part Of: Europhysics letters. Volume 127:Number 6(2019)
• Publication Date: 2019-11-07
• Subjects: 73.43.Nq -- 73.22.-f -- 71.70.-d; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/127/67002
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: We theoretically investigate the effect of an attractive on-site interaction on the two-band magnetic Dirac fermion model based on a square-lattice system. When the attractive fermion interaction is taken into account by the mean-field approximation, a phase diagram is obtained, furthermore it is found that a quantum phase transition from a band insulator state to the quantum anomalous Hall state occurs with increasing attractive interaction. For an existing quantum anomalous Hall state, the attractive interaction enlarges its nontrivial band gap and makes the topological edge states more localized, which protects the transport of linear-dispersive edge states against finite-size and further disorder effects.