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arXiv · 1403.0496

Origin of band gaps in graphene on hexagonal boron nitride

Jeil Jung·Ashley DaSilva·Allan H. MacDonald·Shaffique Adam
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Abstract

Recent progress in preparing well controlled 2D van der Waals heterojunctions has opened up a new frontier in materials physics. In this paper we address the intriguing energy gaps that are sometimes observed when a graphene sheet is placed on a hexagonal boron nitride substrate, demonstrating that they are produced by an interesting interplay between structural and electronic properties, including electronic many-body exchange interactions. Our theory is able to explain the observed gap behavior by accounting first for the structural relaxation of graphene's carbon atoms when placed on a boron nitride substrate and then for the influence of the substrate on low-energy $π$-electrons located at relaxed carbon atom sites. The methods we employ can be applied to many other van der Waals heterojunctions.

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Jeil Jung, Ashley DaSilva, Allan H. MacDonald, Shaffique Adam. 2014-07-27. Origin of band gaps in graphene on hexagonal boron nitride. https://doi.org/10.1038/ncomms7308

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