Download Evolution of edge states during the transition from the quantum spin

Evolution of edge states during the transition from the quantum spin Hall insulators to the
antiferromagnetic Mott insulator
(poster #: )
Hyeong Jun Lee1*, Moo Young Choi1, and Gun Sang Jeon2
1
Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National
University, Seoul 151-747, Korea
2
Department of Physics, Ewha Womans University, Seoul 120-750, Korea
*Email of Presenting Author: [email protected]
In a ribbon geometry, the edges have a current flowing state due to the spin-orbit
interaction while a magnetic and insulating state can appear in the edge in the presence of
the Hubbard interaction. We examine the edge properties in the presence of both
interactions within the Hartree-Fock approximation. We find that the edge magnetic state
shows characteristic behaviors corresponding to the bulk phases, the quantum spin Hall
insulating phase and the antiferromagnetic Mott insulating state. Particularly, in the phase
boundary the edge state exhibits an apparent power-law decay of the local magnetization.
We quantify the resulting magnetic profile across the ribbon by its localization length. It
turns out that the length is dependent on both the electron-electron and spin-orbit
interaction and that it diverges on the boundary between the topological insulator and the
antiferromagnetic insulator.