Topological valley currents via ballistic edge modes in graphene superlattices near the primary Dirac point
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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Date
2020-12-04
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en
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7
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Communications Physics, Volume 3, issue 1
Abstract
Graphene on hexagonal boron nitride (hBN) can exhibit a topological phase via mutual crystallographic alignment. Recent measurements of nonlocal resistance (Rnl) near the secondary Dirac point (SDP) in ballistic graphene/hBN superlattices have been interpreted as arising due to the quantum valley Hall state. We report hBN/graphene/hBN superlattices in which Rnl at SDP is negligible, but below 60 K approaches the value of h/2e2 in zero magnetic field at the primary Dirac point with a characteristic decay length of 2 μm. Furthermore, nonlocal transport transmission probabilities based on the Landauer-Büttiker formalism show evidence for spin-degenerate ballistic valley-helical edge modes, which are key for the development of valleytronics.Description
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Li, Y, Amado, M, Hyart, T, Mazur, G P & Robinson, J W A 2020, ' Topological valley currents via ballistic edge modes in graphene superlattices near the primary Dirac point ', Communications Physics, vol. 3, no. 1, 224 . https://doi.org/10.1038/s42005-020-00495-y