Zero-energy modes and gate-tunable gap in graphene on hexagonal boron nitride

By Markus Kindermann, B. Uchoa, D. Miller. 2012

134 citations recorded by the source corpus.

In this article, we derive an effective theory of graphene on a hexagonal boron nitride (h-BN) substrate. We show that the h-BN substrate generically opens a spectral gap in graphene despite the lattice mismatch. The origin of that gap is particularly intuitive in the regime of strong coupling between graphene and its substrate, when the low-energy physics is determined by the topology of a network of zero-energy modes. For twisted graphene bilayers, where inversion symmetry is present, this network percolates through the system and the spectrum is gapless. The breaking of that symmetry by h-BN causes the zero-energy modes to close into rings. The eigenstates of these rings hybridize into flat bands with gaps in between. The size of this band gap can be tuned by a gate voltage and it can reach the order of magnitude needed to confine electrons at room temperature.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/7ea74c1ad965c47722e7f7900c989a70c0e5d168

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In Atomic and Molecular Physics, and Optics

In Materials Chemistry

Citations in the corpus

Massive Dirac Fermions and Hofstadter Butterfly in a van der Waals Heterostructure (2013, background): “In contrast to the vast majority of graphene devices, which, with few exceptions[11, 12], are semimetallic with zero-field minimum conductivity∼ 2e(2)/h, all four devices are strongly insulating near the overall charge neutrality point (CNP) (Fig.”
Interlayer interaction in general incommensurate atomic layers (2015, background): “y-diﬀerent lattice constants, leading to the long-period modulation even at zero rotation angle [15, 16, 17, 18, 19, 20, 21]. The electronic structure in graphene-hBN system was theoretically studied [22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35], and the recent transport measurements reve”
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