Light based control of Exciton Polaritons in Van der Waals Semiconductors

ORAL

Abstract

In this work we focus on exciton polaritons in the Van der Waals (vdW) Semiconductor, WS2, under intense femto-second (fs) photo-excitation. Photo-excitation initiates a blueshift of the exciton polariton. This corresponds to an extremely large photo-induced change of the dielectric function. Detailed investigation of the dispersion and the fluence dependence indicate the observed effect arises from light-based control of excitons. The change to the dielectric function evolves over two distinct timescales. On the femtosecond timescale a large coherent contribution is observed. On the picosecond (ps) timescale part of the effect is found to persist. The equilibrium state is fully recovered approximately one hundred ps after the photo-excitation event. The information-rich data-sets available from interrogating the exciton-polariton allow us to explore the pathways toward active control of excitons. Additionally, our experimental approach allows us to access key quantities, such as the group velocity and real-space confinement of the exciton polariton, in the non-equilibrium state. Finally, our findings indicate that strong-light matter interactions in vdW semiconductors may be used to achieve all-optical control of significant magnitude.

–

Presenters

  • Aaron Sternbach

    • Physics, Columbia University
    • Columbia University
    • Department of Physics, Columbia University

Authors

  • Aaron Sternbach

    • Physics, Columbia University
    • Columbia University
    • Department of Physics, Columbia University

  • Simone Latini

    • Max Planck Institute for the Structure and Dynamics of Matter

  • Hannes Huebener

    • Max Planck Institute for the Structure and Dynamics of Matter and Center for Free-Electron Laser Science
    • Max Planck Institute for the Structure and Dynamics of Matter

  • Umberto De Giovannini

    • Max Planck Institute for the Structure and Dynamics of Matter

  • Sanghoon Chae

    • Mechanical Engineering, Columbia University

  • Lin Xiong

    • Physics, Columbia University
    • Columbia University

  • Yinming Shao

    • Department of Physics, Columbia University
    • Physics, Columbia University
    • Columbia University

  • Norman Shi

    • Columbia University

  • GuangXin Ni

    • Physics, Columbia University
    • Columbia University

  • Nanfang Yu

    • Columbia University
    • Applied Physics and Applied Mathematics, Columbia University

  • Michael Fogler

    • University of California, San Diego
    • Physics, University of California, San Diego
    • University of California San Diego
    • UC San Diego

  • James Hone

    • Columbia University
    • Mechanics, Columbia University
    • Department of Mechanical Engineering, Columbia University in the City of New York
    • Department of Mechanical Engineering, Columbia University
    • Department of Mechanical Engineering, Columbia University, New York, NY 10027 USA
    • Mechanical Engineering, Columbia University

  • Angel Rubio

    • Max Planck Institute for the Structure and Dynamics of Matter
    • Max Planck Institute for the Structure and Dynamics of Matter and Center for Free-Electron Laser Science
    • Max-Planck Institute for the structure and dynamics of matter
    • Max Planck Inst Structure & Dynamics of Matter
    • Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
    • Universidad del País Vasco UPV/EHU and Max Planck Institute for the Structure and Dynamics of Matter
    • Theory, Max Planck Institute for the Structure and Dynamics of Matter (MPSD)

  • Dimitri Basov

    • Department of Physics, Columbia University in the City of New York
    • Department of Physics, Columbia University, New York 10027
    • department of physics, columbia university
    • Department of Physics, Columbia University
    • Physics, Columbia University
    • Columbia University