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arXiv · 1404.4019

Topological Bloch Bands in Graphene Superlattices

Justin C. W. Song·Polnop Samutpraphoot·Leonid S. Levitov
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Abstract

We outline an approach to endow a plain vanilla material with topological properties by creating topological bands in stacks of manifestly nontopological atomically thin materials. The approach is illustrated with a model system comprised of graphene stacked atop hexagonal-boron-nitride. In this case, the Berry curvature of the electron Bloch bands is highly sensitive to the stacking configuration. As a result, electron topology can be controlled by crystal axes alignment, granting a practical route to designer topological materials. Berry curvature manifests itself in transport via the valley Hall effect and long-range chargeless valley currents. The non-local electrical response mediated by such currents provides diagnostics for band topology.

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Justin C. W. Song, Polnop Samutpraphoot, Leonid S. Levitov. 2015-06-03. Topological Bloch Bands in Graphene Superlattices. https://doi.org/10.1073/pnas.1424760112

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