Boundary Modes from Periodic Magnetic and Pseudomagnetic Fields in Graphene

Single-layer graphene subject to periodic lateral strains is an artificial crystal that can support boundary spectra with an intrinsic polarity. This is analyzed by comparing the effects of periodic magnetic fields and strain-induced pseudomagnetic fields that, respectively, break and preserve time-...

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Bibliographic Details
Published inPhysical review letters Vol. 128; no. 17; p. 176406
Main Authors Phong, Võ Tiến, Mele, E J
Format Journal Article
LanguageEnglish
Published United States 29.04.2022
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Summary:Single-layer graphene subject to periodic lateral strains is an artificial crystal that can support boundary spectra with an intrinsic polarity. This is analyzed by comparing the effects of periodic magnetic fields and strain-induced pseudomagnetic fields that, respectively, break and preserve time-reversal symmetry. In the former case, a Chern classification of the superlattice minibands with zero total magnetic flux enforces single counterpropagating modes traversing each bulk gap on opposite boundaries of a nanoribbon. For the pseudomagnetic field, pairs of counterpropagating modes migrate to the same boundary where they provide well-developed valley-helical transport channels on a single zigzag edge. We discuss possible schemes for implementing this situation and their experimental signatures.
ISSN:1079-7114
DOI:10.1103/PhysRevLett.128.176406