Ultrafast Optical Spectroscopy of Epitaxial LaVO<sub>3</sub> Thin Films: Evidence for Critical Dynamics

ORAL

Abstract

We investigate time-resolved dynamics in perovskite-type LaVO3 thin film samples using femtosecond pump-probe spectroscopy. LaVO3 is a Mott-Hubbard (MH) insulator that undergoes a magnetic transition at 143 K (paramagnetic to antiferromagnetic) and a structural phase transition at 141 K, below which orbital ordering occurs1. Excitation of carriers across the MH gap with ~50 fs pulses initiates dynamics that manifest as changes in the reflectivity. In the vicinity of the magnetic transition, we observe dramatic slowing down in the recovery dynamics, consistent with critical-like dynamics at a 2nd order phase transition2, likely related to spin-ordering dynamics3. Further, we observe coherent acoustic phonons which also exhibit an anomalous response near ~140K.

1S. Tomimito, et al, Physical Review B 68, 035106 (2003)
2R. V. Yusupov, et al, Physical Review B 81, 075103 (2010)
3D. M. Mazurenko, et al, Physical Review Letters 101, 245702 (2008)

*Research supported by DOE-BES under DE-SC0012375

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Presenters

  • Dylan Lovinger

    • Department of Physics, Univ of California - San Diego

Authors

  • Dylan Lovinger

    • Department of Physics, Univ of California - San Diego

  • Matthew Brahlek

    • Material Science, Pennsylvania State University
    • Pennsylvania State University
    • Physics, Pennsylvania State Univ
    • Materials Science and Engineering, Pennsylvania State University
    • Department of Materials Science and Engineering, Pennsylvania State University
    • Materials Science, Pennsylvania State University

  • Roman Engel-Herbert

    • Department of Materials Science and Engineering, Pennsylvania State Univ
    • Material Science, Pennsylvania State University
    • Physics, Pennsylvania State University
    • Materials Science and Engineering, Pennsylvania State Universtiy
    • Pennsylvania State University
    • Physics, Pennsylvania State Univ
    • Materials Science and Engineering, Pennsylvania State University
    • Department of Materials Science and Engineering, Pennsylvania State University
    • Materials Science, Pennsylvania State University

  • Richard Averitt

    • Physics, University of California, San Diego
    • Physics, Univ of California - San Diego
    • Univ of California - San Diego
    • Department of Physics, University of California San Diego
    • Department of Physics, Univ of California - San Diego
    • University of California San Diego