Open AccessPhase transition of ultrathin Bi2Se3 film sandwiched between ferromagnetic insulators
Author(s) -
Huaiqiang Wang,
Yongzhen Yang,
Ju Yan,
Sheng Li,
Xing Ding-Yu
Publication year - 2013
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.62.037202
Subject(s) - condensed matter physics , topological insulator , ribbon , ferromagnetism , materials science , antiparallel (mathematics) , quantum anomalous hall effect , hamiltonian (control theory) , quantum hall effect , phase transition , electron , band gap , physics , magnetic field , quantum mechanics , mathematical optimization , mathematics , composite material
For an ultra-thin Bi2Se3 film sandwiched between two ferromagnetic insulators (FIs), we investigate how its topological properties change with the angle between the magnetizations of the two FIs. The Chern numbers are calculated from the low-energy effective Hamiltonian for electrons in the surface states, and the bulk energy band and the edge states are simulated from the tight-binding model of a long ribbon with armchair edges on a two-dimensional honeycomb lattice, from which the topological phase of the system can be determined. It is found that with the magnetizations of the FIs varying from parallel to antiparallel, there appears a topological phase transition from the anomalous quantum Hall phase to the trivial insulating one at a critical angle.