Valley splitter and transverse valley focusing in twisted bilayer graphene

Research output: Contribution to journal › Article › Research › peer review

Authors

  • Christophe De Beule
  • Peter G. Silvestrov
  • Ming Hao Liu
  • Patrik Recher

External Research Organisations

  • Technische Universität Braunschweig
  • National Cheng Kung University
  • Laboratory for Emerging Nanometrology Braunschweig (LENA)
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Details

Original languageEnglish
Article number043151
JournalPhysical Review Research
Volume2
Issue number4
Publication statusPublished - 28 Oct 2020
Externally publishedYes

Abstract

We study transport in twisted bilayer graphene and show that electrostatic barriers can act as valley splitters, where electrons from the K (K′) valley are transmitted only to, e.g., the top (bottom) layer, leading to valley-layer locked currents. We show that such a valley splitter is obtained when the barrier varies slowly on the moiré scale and induces a Lifshitz transition across the junction, i.e., a change in the Fermi-surface topology. Furthermore, we show that for a given valley the reflected and transmitted current are transversely deflected, as time-reversal symmetry is effectively broken in each valley separately, resulting in valley-selective transverse focusing at zero magnetic field.

ASJC Scopus subject areas

Cite this

Valley splitter and transverse valley focusing in twisted bilayer graphene. / De Beule, Christophe; Silvestrov, Peter G.; Liu, Ming Hao et al.
In: Physical Review Research, Vol. 2, No. 4, 043151, 28.10.2020.

Research output: Contribution to journal › Article › Research › peer review

De Beule, C, Silvestrov, PG, Liu, MH & Recher, P 2020, 'Valley splitter and transverse valley focusing in twisted bilayer graphene', Physical Review Research, vol. 2, no. 4, 043151. https://doi.org/10.1103/PhysRevResearch.2.043151
De Beule, C., Silvestrov, P. G., Liu, M. H., & Recher, P. (2020). Valley splitter and transverse valley focusing in twisted bilayer graphene. Physical Review Research, 2(4), Article 043151. https://doi.org/10.1103/PhysRevResearch.2.043151
De Beule C, Silvestrov PG, Liu MH, Recher P. Valley splitter and transverse valley focusing in twisted bilayer graphene. Physical Review Research. 2020 Oct 28;2(4):043151. doi: 10.1103/PhysRevResearch.2.043151
De Beule, Christophe ; Silvestrov, Peter G. ; Liu, Ming Hao et al. / Valley splitter and transverse valley focusing in twisted bilayer graphene. In: Physical Review Research. 2020 ; Vol. 2, No. 4.
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AU - Recher, Patrik

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