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.

*I.C.T., Q.Z., K.S., G.C., X. X., H.W. acknowledge the support from the Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-SC0012509. AK, HK, AN, FS, RKK and PV acknowledge support of the Computational Materials Sciences Program funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award Number DE-SC0014607.

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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