Tip-enhanced radiative control of dark and localized excitons in atomically thin semiconductors at room temperature

ORAL

Abstract

Dark excitons, XD, in semiconductors are appealing candidates for quantum computing and optoelectronics owing to their long lifetimes. However, optical read-out and control of XD states has remained challenging due to their decoupling from light. Here, we present a tip-enhanced nano-optical approach to induce and control the radiative emission of XD at room temperature. Using a monolayer (ML) WSe2 on a gold substrate, we demonstrate ~6×105-fold photoluminescence (PL) enhancement through coupling of the antenna-tip to the dark exciton out-of-plane optical dipole moment, with large Purcell factor of ≥2×103 of the tip-sample nano-cavity. As an extension experiment of the tip-enhanced PL (TEPL) of WSe2 ML, we control the radiative emission of localized exciton (XL) with 10 nm spatial resolution nano-imaging to understand unique quantum emitting properties of XL in space and time. Our approach provides a new and facile way to harness excitonic properties in low-dimensional semiconductors offering new strategies for quantum optoelectronics.

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Presenters

  • Kyoung-Duck Park

    • Department of Physics, Department of Chemistry, and JILA, University of Colorado - Boulder
    • Physics, Univ of Colorado - Boulder
    • Physics, Chemistry, and JILA, Univ of Colorado

Authors

  • Kyoung-Duck Park

    • Department of Physics, Department of Chemistry, and JILA, University of Colorado - Boulder
    • Physics, Univ of Colorado - Boulder
    • Physics, Chemistry, and JILA, Univ of Colorado

  • Tao Jiang

    • Department of Physics, Department of Chemistry, JILA, and Center for Experiments on Quantum Materials, Univ of Colorado - Boulder
    • Fudan University
    • Physics, Chemistry, and JILA, Univ of Colorado

  • Genevieve Clark

    • Department of Physics, University of Washington
    • Materials Science and Engineering, University of Washington
    • Physics, and Materials Science and Engineering, Univ of Washington

  • Xiaodong Xu

    • University of Washington
    • Univ of Washington
    • Physics, Univ of Washington
    • Department of Physics, University of Washington
    • Physics, University of Washington
    • Physics, and Materials Science and Engineering, Univ of Washington
    • Department of Physics, University of Washington - Seattle

  • Markus Raschke

    • Physics, Chemistry, and JILA, Univ of Colorado