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arXiv · 1702.03107

Emergence of Tertiary Dirac Points in Graphene Moir\'e Superlattices

Guorui Chen·Mengqiao Sui·Duoming Wang·Shuopei Wang·Jeil Jung·Pilkyung Moon·Shaffique Adam·Kenji Watanabe·Takashi Taniguchi·Shuyun Zhou·Mikito Koshino·Guangyu Zhang·Yuanbo Zhang
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Abstract

The electronic structure of a crystalline solid is largely determined by its lattice structure. Recent advances in van der Waals solids, artificial crystals with controlled stacking of two-dimensional (2D) atomic films, have enabled the creation of materials with novel electronic structures. In particular, stacking graphene on hexagonal boron nitride (hBN) introduces moir\'e superlattice that fundamentally modifies graphene's band structure and gives rise to secondary Dirac points (SDPs). Here we find that the formation of a moir\'e superlattice in graphene on hBN yields new, unexpected consequences: a set of tertiary Dirac points (TDPs) emerge, which give rise to additional sets of Landau levels when the sample is subjected to an external magnetic field. Our observations hint at the formation of a hidden Kekul\'e superstructure on top of the moir\'e superlattice under appropriate carrier doping and magnetic fields.

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Guorui Chen, Mengqiao Sui, Duoming Wang, Shuopei Wang, Jeil Jung, Pilkyung Moon, Shaffique Adam, Kenji Watanabe, Takashi Taniguchi, Shuyun Zhou, Mikito Koshino, Guangyu Zhang, Yuanbo Zhang. 2017-02-10. Emergence of Tertiary Dirac Points in Graphene Moir\'e Superlattices. https://doi.org/10.1021/acs.nanolett.7b00735

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