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Imaging strain-localized exciton states in nanoscale bubbles in monolayer transition metal dichalcogenides at room temperature

ORAL

Abstract

In monolayer transition metal dichalcogenides (1L-TMD’s), applied strain can deterministically create quantum emitters at arbitrary sites on-demand. Despite a robust empirical correlation with strain, the nanoscopic details of these quantum emitters are poorly understood. Here we combine room-temperature nano-optical imaging of excitons in nanobubbles in 1L-WSe2 with atomistic structural models to elucidate how strain induces the nanoscale confinement potentials that give rise to highly localized exciton states in 2D semiconductors. Nano-optical imaging reveals localized excitons on length scales of ~10 nm at multiple sites along the periphery of individual nanobubbles, which is in stark contrast to predictions of continuum strain models. These results agree with theoretical confinement potentials derived from measured topographies of nanobubbles. We reproduce these findings in nanobubbles of low-defect WSe2 and MoSe2, suggesting our results are applicable to excitons in all the semiconducting 1L-TMD’s. Our results provide one-of-a-kind insight of how strain-induced confinement—without crystalline defects—can localize excitons on length scales commensurate with exciton size, providing key nanoscale structure-property information for quantum emitter phenomena in 1L-TMD’s.

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Presenters

  • Thomas Darlington

    Columbia University, University of California, Berkeley, Mechanical Engineering, Columbia University

Authors

  • Thomas Darlington

    Columbia University, University of California, Berkeley, Mechanical Engineering, Columbia University

  • Christian Carmesin

    Institute for Theoretical Physics, University of Bremen

  • Mathias Florian

    Institute for Theoretical Physics, University of Bremen

  • Emanuil Yanev

    Columbia University, Mechanical Engineering, Columbia University

  • Demi Ajayi

    Mechanical Engineering, Columbia University

  • Jenny Ardelean

    Mechanical Engineering, Columbia University

  • Augusto Ghiotto

    Columbia University, Columbia Univ, Physics, Columbia University, Department of Physics, Columbia University

  • Andrey Krayev

    HORIBA Scientific, Horiba Scientific

  • Jeffrey Kysar

    Mechanical Engineering, Columbia University

  • Abhay Pasupathy

    Columbia University, Physics Department, Columbia University, Columbia Univ, Department of Physics, Columbia University, New York, New York 10027, USA, Physics, Columbia University, Department of Physics, Columbia University

  • James C Hone

    Columbia University, Mechanical Engineering, Columbia University, Columbia Univ, Physics, Columbia University, Columbia University, NY, USA, Department of Mechanical Engineering, Columbia University

  • Frank Jahnke

    Institute for Theoretical Physics, University of Bremen

  • Nicholas J Borys

    Montana State University, Department of Physics, Montana State University, Montana State University, Bozeman

  • P. James Schuck

    Columbia University, Mechanical Engineering, Columbia University