Topological Bloch Bands in Graphene Superlattices
Abstract
We outline a designer approach to endow widely available plain materials with topological properties by stacking them atop other nontopological materials. The approach is illustrated with a model system comprising 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 nonlocal electrical response mediated by such currents provides diagnostics for band topology.
Additional Information
© 2015 National Academy of Sciences. Edited by Subir Sachdev, Harvard University, Cambridge, MA, and approved June 24, 2015 (received for review December 30, 2014). Published online before print August 18, 2015. This work was supported by National Science Foundation (NSF) Science and Technology Center for Integrated Quantum Materials, NSF Grant DMR-1231319 (to L.S.L.), and in part by the US Army Research Laboratory and the US Army Research Office through the Institute for Soldier Nanotechnologies, under Contract no. W911NF-13-D-0001 (L.S.L.). J.C.W.S. acknowledges support from a Burke Fellowship at Caltech, the Sherman Fairchild Foundation, and a National Science Scholarship. Author contributions: J.C.W.S. and L.S.L. designed research; J.C.W.S., P.S., and L.S.L. performed research; and J.C.W.S. and L.S.L. wrote the paper. The authors declare no conflict of interest. This article is a PNAS Direct Submission. This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1424760112/-/DCSupplemental.Attached Files
Published - PNAS-2015-Song-10879-83.pdf
Submitted - song_4.pdf
Supplemental Material - pnas.201424760SI.pdf
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Additional details
- PMCID
- PMC4568281
- Eprint ID
- 58759
- Resolver ID
- CaltechAUTHORS:20150702-144749667
- DMR-1231319
- NSF
- W911NF-13-D-0001
- Army Research Office (ARO)
- Walter Burke Institute for Theoretical Physics, Caltech
- Sherman Fairchild Foundation
- National Science Scholarship
- Created
-
2015-07-06Created from EPrint's datestamp field
- Updated
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2022-05-24Created from EPrint's last_modified field
- Caltech groups
- Institute for Quantum Information and Matter, Walter Burke Institute for Theoretical Physics