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arXiv · 1012.0655

Topological Insulators from Spontaneous Symmetry Breaking Induced by Electron Correlation on Pyrochlore Lattices

Moyuru Kurita·Youhei Yamaji·Masatoshi Imada
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Abstract

We study an extended Hubbard model with the nearest-neighbor Coulomb interaction on the pyrochlore lattice at half filling. An interaction-driven insulating phase with nontrivial Z_2 invariants emerges at the Hartree-Fock mean-field level in the phase diagram. This topological insulator phase competes with other ordered states and survives in a parameter region surrounded by a semimetal, antiferromagnetic and charge ordered insulators. The symmetries of these phases are group-theoretically analyzed. We also show that the ferromagnetic interaction enhances the stability of the topological phase.

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Moyuru Kurita, Youhei Yamaji, Masatoshi Imada. 2011-02-25. Topological Insulators from Spontaneous Symmetry Breaking Induced by Electron Correlation on Pyrochlore Lattices. https://doi.org/10.1143/jpsj.80.044708

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