Anisotropic structural dynamics of monolayer crystals revealed by femtosecond surface x-ray scattering

ORAL

Abstract

The direct structural characterization of nonequilibrium processes within a monolayer crystal remains a challenge due to significantly reduced scattering volume. In this work, we demonstrate femtosecond surface x-ray diffraction in combination with crystallographic model-refinement calculations to measure the ultrafast structural dynamics of monolayer WSe2 crystals on a substrate. We found the absorbed photon energy is preferably coupled to the in-plane lattice vibrations within 2 picoseconds while the out-of-plane lattice vibration amplitude remains unchanged during the first 10 picoseconds. The model-assisted fitting suggests an asymmetric intralayer spacing change upon excitation. The demonstrated methods unlock the benefit of x-ray scattering to quantitatively measure ultrafast structural dynamics in atomically thin materials and across interfaces.

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Presenters

  • Haidan Wen

    Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA, X-ray Science Division,, Argonne National Laboratory

Authors

  • I-Cheng Tung

    Argonne National Laboratory

  • Aravind Krishnamoorthy

    University of Southern California, Physics & Astronomy, University of Southern California

  • Sridhar Sadasivam

    Argonne National Laboratory

  • Hua Zhou

    Advanced Photon Source, Argonne National Laboratory, X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne National Lab, Argonne National Laboratory

  • Qi Zhang

    Argonne National Laboratory, Electrical Engineering, Rice University

  • Kyle Seyler

    University of Washington, Seattle, Univ of Washington

  • Genevieve Clark

    University of Washington, Seattle

  • Ehren Mannebach

    Stanford University

  • Clara M Nyby

    Stanford University

  • Friederike Ernst

    Stanford University

  • Diling Zhu

    SLAC National Accelerator Laboratory, SLAC- Natl Accelerator Lab

  • James M Glownia

    SLAC National Accelerator Laboratory

  • Michael E Kozina

    SLAC National Accelerator Laboratory

  • Sanghoon Song

    SLAC National Accelerator Laboratory

  • Silke Nelson

    SLAC National Accelerator Laboratory

  • Hiroyuki Kumazoe

    Kumamoto University

  • Fuyuki Shimojo

    Kumamoto University

  • Rajiv Kalia

    University of Southern California, Physics, University of Southern California, Physics & Astronomy, University of Southern California

  • Priya Vashishta

    University of Southern California, Physics, University of Southern California, Collaboratory for Advanced Computing and Simulations, University of Southern California, Physics & Astronomy, University of Southern California

  • Pierre Darancet

    Center for Nanoscale Materials, Argonne National Laboratory, Argonne National Laboratory

  • Tony F Heinz

    Stanford University & SLAC National Accelerator Laboratory, Department of Applied Physics, Stanford University, Stanford, California, 94305 USA, Applied Physics, Stanford University, Stanford University and SLAC National Laboratory, Stanford University, Stanford University & SLAC

  • Aiichiro Nakano

    University of Southern California, Physics, University of Southern California, Physics & Astronomy, University of Southern California

  • Xiaodong Xu

    University of Washington, Department of Physics, University of Washington, University of Washington, Seattle

  • Aaron M Lindenberg

    Stanford University

  • Haidan Wen

    Argonne National Laboratory, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA, X-ray Science Division,, Argonne National Laboratory