Ultrafast Optical Spectroscopy of Epitaxial LaVO3 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)

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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