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arXiv · 2006.13946

Classification of Topological Phase Transitions and van Hove Singularity Steering Mechanism in Graphene Superlattices

Jian Wang·Luiz H. Santos
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Abstract

We study quantum phase transitions in graphene superlattices in external magnetic fields, where a framework is presented to classify multiflavor Dirac fermion critical points describing hopping tuned topological phase transitions of integer and fractional Hofstadter-Chern insulators. We argue and provide numerical support for the existence of transitions that can be explained by a nontrivial interplay of Chern bands and van Hove singularities near charge neutrality. This work provides a route to critical phenomena beyond conventional quantum Hall plateau transitions.

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Jian Wang, Luiz H. Santos. 2020-06-24. Classification of Topological Phase Transitions and van Hove Singularity Steering Mechanism in Graphene Superlattices. https://doi.org/10.1103/physrevlett.125.236805

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