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arXiv · 1701.02441

Two-component quantum Hall effects in topological flat bands

Tian-Sheng Zeng·W. Zhu·D. N. Sheng
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Abstract

We study quantum Hall states for two-component particles (hardcore bosons and fermions) loading in topological lattice models. By tuning the interplay of interspecies and intraspecies interactions, we demonstrate that two-component fractional quantum Hall states emerge at certain fractional filling factors $ν=1/2$ for fermions ($ν=2/3$ for bosons) in the lowest Chern band, classified by features from ground states including the unique Chern number matrix (inverse of $\mathbf{K}$-matrix), the fractional charge and spin pumpings, and two parallel propagating edge modes. Moreover, we also apply our strategy to two-component fermions at integer filling factor $ν=2$, where a possible topological Neel antiferromagnetic phase is under intense debate very recently. For the typical $π$-flux checkerboard lattice, by tuning the onsite Hubbard repulsion, we establish a first-order phase transition directly from a two-component fermionic $ν=2$ quantum Hall state at weak interaction to a topologically trivial antiferromagnetic insulator at strong interaction, and therefore exclude the possibility of an intermediate topological phase for our system.

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Tian-Sheng Zeng, W. Zhu, D. N. Sheng. 2017-03-28. Two-component quantum Hall effects in topological flat bands. https://doi.org/10.1103/physrevb.95.125134

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