Spontaneous quantum Hall effect in quarter-doped Hubbard model on honeycomb lattice and its possible realization in doped graphene system

Author： Li Tao

Publisher： Edp Sciences

E-ISSN： 1286-4854|97|3|37001-37001

ISSN： 0295-5075

Source： EPL (EUROPHYSICS LETTERS), Vol.97, Iss.3, 2012-02, pp. : 37001-37001

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Abstract

We show that a magnetic insulating state with nonzero spin chirality is realized in a quarter-doped Hubbard model on honeycomb lattice as a result of the nesting property of the Fermi surface. This state is topological nontrivial and has a quantized Hall conductance of $\sigma_{xy}=\frac{e^{2}}{h} $. We find that such a state is robust against next-nearest-neighboring hopping and we propose that it can be realized in a quarter-doped graphene system. We also show that the quarter-doped Hubbard model on honeycomb lattice is equivalent to a 3/4-filled Hubbard model on triangular lattice in the weak coupling limit, in which a similar effect was predicted previously.