Exciton Hall effect and valley-exciton transport

ORAL

Abstract

Spontaneous Hall effect caused by the Berry curvature (the internal magnetic field in momentum space) has recently attracted vast interest for investigating internal quantum degrees of freedom in solids. Here we report a new type of spontaneous Hall effect, exciton Hall effect (EHE), in monolayer MoS2[1].
The valley-coupled excitons in transition metal dichalcogenides are expected to possess valley-contrasting Berry curvature, which gives rise the Hall effect of valley excitons without magnetic fields. We observed the EHE and valley-contrasting exciton transport in a micrometer scale by using polarization-resolved photoluminescence mapping. The valley diffusion length is deduced to be around 2 μm at 30 K in monolayer MoS2. The EHE and the consequent valley transport can push ahead exciton-based valleytronics in two-dimensional materials.
[1] M. Onga et al., Nat. Mater. (2017). doi:10.1038/nmat4996.

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Presenters

  • Masaru Onga

    University of Tokyo, Univ. of Tokyo

Authors

  • Masaru Onga

    University of Tokyo, Univ. of Tokyo

  • Yijin Zhang

    Max Planck Institute for Solid State Research, Max-Planck-Institut für Festkörperforschung

  • Toshiya Ideue

    The University of Tokyo, the University of Tokyo, the Univ. of Tokyo, Univ. of Tokyo

  • Yoshihiro Iwasa

    Univ of Tokyo, Department of Applied Physics, The University of Tokyo, The University of Tokyo, University of Tokyo, The Univ. of Tokyo, the University of Tokyo, the Univ. of Tokyo, Univ. of Tokyo