Tuesday, April 24, 2012

1204.4766 (Jing He et al.)

Ferromagnetism and Antiferromagnetism of Correlated Topological
Insulator with Flat Band
   [PDF]

Jing He, Bo Wang, Su-Peng Kou
In this paper, based on the mean field approach and random-phase-approximation, we study the magnetic properties of the spinful Haldane model on honeycomb lattice of topological flat band with on-site repulsive Coulomb interaction. We find that the antiferromagnetic (AF) order is more stable than ferromagnetic (FM) order at (or near) half-filling; while away from half-filling the phase diagram becomes complex: At large doping, FM order is more stable than AF order due to the flatness of band structure. In particular, we find that at quarter filling case, the system becomes a Q=1$ topological insulator which is induced by the FM order.
View original: http://arxiv.org/abs/1204.4766

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