Interlayer Exciton Traps in Van der Waals Heterostructures

ORAL

Abstract

Two-dimensional (2D) van der Waals materials such as single layer transition metal dichalcogenides (TMDs) and hexagonal boron nitride (BN) have sparked interest in the study of atomically thin semiconducting heterostructures. The 2D nature and large excitonic binding energy of TMDs allow for the exploration of novel quantum optical effects. Using type-II heterostructures formed by stacking MoSe2 and WSe2 monolayers, we study interlayer excitons, bound electrons and holes residing in spatially separated layers. We fabricate dual-gated, BN encapsulated devices with electrical contacts in each layer, giving us pristine samples with full electrical control. Interlayer excitons in our heterostructures have near-infrared energies and lifetimes on the order of 100ns, both of which can be tunable using out-of-plane electric field. We observe localization of interlayer excitons in naturally formed traps that have longer lifetimes and higher intensities than in the non-localized regions. In addition, we can form artificial traps through confinement potentials using out-of-plane electric fields. Because of the large binding energies, interlayer excitons can serve as a platform for exploring the physics of light-matter interactions and Bose-Einstein condensates at high temperatures.

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Presenters

  • Andrew Joe

    Physics, Harvard University, Harvard University

Authors

  • Andrew Joe

    Physics, Harvard University, Harvard University

  • Luis Jauregui

    Department of Physics, Harvard University, Harvard Univ, Physics, Harvard University, Harvard University

  • Kateryna Pistunova

    Department of Physics, Harvard University, Physics, Harvard University, Harvard Univ, Harvard University

  • Alexander High

    Institute for Molecular Engineering, University of Chicago, Physics, Harvard University, Harvard University, The Institute for Molecular Engineering, University of Chicago

  • You Zhou

    Harvard Univ, Physics, Harvard University, Physics, Chemistry and Chemical Biology, Harvard University, Harvard University

  • Giovanni Scuri

    Harvard Univ, Physics, Harvard University, Harvard University

  • Kristiaan De Greve

    Harvard Univ, Physics, Harvard University, Harvard University

  • Dominik Wild

    Harvard Univ, Physics, Harvard University, Harvard University

  • Eshaan Patheria

    Department of Physics, Harvard University, Harvard University, Physics, Harvard University

  • Mikhail Lukin

    Harvard University, Physics, Harvard Univ, Harvard Univ, Department of Physics, Harvard University, Physics, Harvard University

  • Hongkun Park

    Harvard Univ, Physics, Harvard University, Physics, Chemistry and Chemical Biology, Harvard University, Harvard University, Chemistry and Physics, Harvard University

  • Philip Kim

    Physics, Harvard University, Harvard University, Department of Physics, Harvard University, Harvard Univ, Physics, Harvard, Department of Physics, Harvard university, School of Applied Sciences and Engineering, Harvard University