Coherent lattice motion in freestanding perovskite films probed by ultrafast electron diffraction

ORAL

Abstract

Advances in femtosecond lasers make it possible to coherently generate specific phonon modes in crystals. These coherent lattice vibrations enable one to pinpoint specific atomic motion on the picometer scale, and this knowledge, in turn, helps one to realize ultrafast control of material property by laser pulses. In this experiment, we performed ultrafast electron diffraction on a 20-nm freestanding film of La0.67Ca0.33MnO3. Following photoexcitation, we observed a 0.15 THz acoustic phonon extracted from Bragg peak intensity, position and width. By tracing the coherent oscillations in these three channels for more than 20 Bragg peaks, we are able to reconstruct in real space the unconventional atomic trajectory following the arrival of the laser pulse.

*Gordon and Betty Moore Foundation; U.S. Department of Energy

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Presenters

  • Yifan Su

    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT

Authors

  • Yifan Su

    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT

  • Alfred Zong

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • Physics, MIT

  • Anshul Kogar

    • Massachusetts Institute of Technology
    • Massachusetts Institute of Technology MIT

  • Di Lu

    • Stanford University
    • Physics, Stanford University

  • Seung Sae Hong

    • Stanford University
    • Department of Applied Physics, Stanford University
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory & Stanford University

  • Harold Hwang

    • Institute for Materials and Energy Sciences, Stanford University
    • Stanford University
    • Department of Applied Physics, Stanford University
    • Applied Physics, Stanford University
    • SIMES, SLAC
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
    • SLAC National Accelerator Lab.
    • Physics, Stanford University
    • Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory

  • Nuh Gedik

    • Massachusetts Institute of Technology MIT
    • Massachusetts Institute of Technology
    • Physics, MIT