High temperature quantum transport in 2D moiré superlattices

ORAL

Abstract

Van der Waals heterostructures based on moiré superlattices have become increasingly popular due to their large tunability unprecedented by any other solid-state system. In this talk, we review recent experimental results on high-temperature electron transport studies in heterostructures based on 2D moiré superlattices. Our experiments describe two fundamental phenomena of electron transport that manifest profoundly at high temperatures and are extremely sensitive to the twist-angle. First, we show that electron-electron collisions in graphene superlattices are dominated by umklapp processes [1]. They cause a giant increase in resistivity that grows rapidly upon decreasing the twist-angle between 2D layers, degrading the intrinsic mobility of graphene by more than an order of magnitude. Second, we show that moiré superlattices feature a novel class of quantum magnetoresistance oscillations [2] that differ fundamentally from the Shubnikov de Haas effect and all known quantum oscillatory phenomena.

[1] J. Wallbank, R. Krishna Kumar et al. Nature Physics (2018)
[2] R. Krishna Kumar, et al. PNAS. 115 , 5135-5139 (2018)

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Presenters

  • Roshan Krishna Kumar

    School of Physics & Astronomy, University of Manchester

Authors

  • Roshan Krishna Kumar

    School of Physics & Astronomy, University of Manchester

  • John Wallbank

    University of Manchester, UK, School of Physics & Astronomy, University of Manchester

  • Xi Chen

    School of Physics & Astronomy, University of Manchester

  • Gregory Auton

    School of Physics & Astronomy, University of Manchester

  • Matthew Holwill

    School of Physics & Astronomy, University of Manchester

  • Artem Mishchenko

    School of Physics and Astronomy, University of Manchester, School of physics and astronomy, the University of Manchester, Physics and Astronomy, The University of Manchester, School of Physics & Astronomy, University of Manchester

  • Konstantin S Novoselov

    School of Physics & Astronomy, University of Manchester

  • 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

  • Andre Geim

    School of physics and astronomy, the University of Manchester, Physics and Astronomy, The University of Manchester, School of Physics & Astronomy, University of Manchester, School of Physics, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom