Electronic contributions to the Raman spectrum of twisted bilayer graphene

ORAL

Abstract

Using the continuum model, we study theoretically the purely electronic contributions to the Raman spectrum of twisted bilayer graphene (tBLG) for twist angles close to the magic angle [1]. We show that non-resonant excitations of electron-hole pairs between the first minibands above and below the neutrality point lead to a peak, the position of which is determined by the twist angle. We estimate the quantum efficiency of this Raman feature as ∼10-13, about two orders of magnitude less than the intensity of the G peak [2]. Because of its electronic origin, the new peak provides direct information about the flatness of the first minibands in tBLG.
[1] R. Bistritzer et al., PNAS 108, 12233-12237, (2011)
[2] D. Basko, Phys. Rev. B 78, 125418 –(2008)

*This contribution has been supported by the UK Engineering and Physical Sciences Research Council (EPSRC) through the Centre for Doctoral Training in Condensed Matter Physics (CDT-CMP), EPSRC Grant No. EP/L015544/1, as well as EPSRC Grant No. EP/N010345/1, the European Graphene Flagship project, and Lloyd’s Register Foundation Nanotechnology Programme.

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Presenters

  • Aitor Garcia-Ruiz

    • Physics, University of Bath

Authors

  • Aitor Garcia-Ruiz

    • Physics, University of Bath

  • Marcin Mucha-Kruczynski

    • Physics, University of Bath

  • Joshua Thompson

    • Physics, University of Bath

  • Vladimir Falko

    • School of physics and astronomy, the University of Manchester
    • University of Manchester, UK
    • School of Physics and Astronomy, University of Manchester
    • School of Physics & Astronomy, University of Manchester
    • National Graphene Institute