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arXiv · 1205.5792

Topological flat band models with arbitrary Chern numbers

Shuo Yang·Zheng-Cheng Gu·Kai Sun·S. Das Sarma
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Abstract

We report the theoretical discovery of a systematic scheme to produce topological flat bands (TFBs) with arbitrary Chern numbers. We find that generically a multi-orbital high Chern number TFB model can be constructed by considering multi-layer Chern number C=1 TFB models with enhanced translational symmetry. A series of models are presented as examples, including a two-band model on a triangular lattice with a Chern number C=3 and an $N$-band square lattice model with $C=N$ for an arbitrary integer $N$. In all these models, the flatness ratio for the TFBs is larger than 30 and increases with increasing Chern number. In the presence of appropriate inter-particle interactions, these models are likely to lead to the formation of novel Abelian and Non-Abelian fractional Chern insulators. As a simple example, we test the C=2 model with hardcore bosons at 1/3 filling and an intriguing fractional quantum Hall state is observed.

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Shuo Yang, Zheng-Cheng Gu, Kai Sun, S. Das Sarma. 2012-12-31. Topological flat band models with arbitrary Chern numbers. https://doi.org/10.1103/physrevb.86.241112

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