Temperature-dependence of hypersound dynamics in SrTiO$_{\mathrm{3}}$/SrRuO$_{\mathrm{3}}$ heterostructures studied by ultrafast spectroscopy

ORAL

Abstract

Strontium titanate (SrTiO$_{\mathrm{3}}$, STO) and strontium ruthenate (SrRuO$_{\mathrm{3}}$, SRO) are complex oxide with perovskite structure. Their property, such as thermoelectricity and superconductivity, has been widely investigated for scientific and industrial purposes. Recently, complex oxide heterostructures can be grown by pulsed laser deposition. It opens many possibilities f or new properties of materials. With ultrafast pump-probe spectroscopy, we demonstrated that metal-like SRO thin film can be served as a phonon transducer to generate hypersound with frequency of several tens to several hundreads of GHz. This technique can be utilized to study not only the elastic properties of perovskite thin films but also the interfaces. In this study, we used this technique to study the temperature dependence of structural phases in STO. During the crossing over the soft-mode transition in STO around 110 K, the shortening of phonon lifetime were also observed.

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Authors

  • Chi-Yuan Yang

    • Institute of Physics, Academia Sinica, Taipei 11529, Taiwan; Department of Physics, National Taiwan University, Taipei 106, Taiwan

  • Ajay K Yadav

    • Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA

  • Ramamoorthy Ramesh

    • Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA

  • Yu-Chieh Wen

    • Institute of Physics, Academia Sinica, Taipei 11529, Taiwan

  • Chia-Hao Hsu

    • Institute of Physics, Academia Sinica, Taipei 11529, Taiwan

  • Maw-Kuen Wu

    • Institute of Physics, Academia Sinica, Taipei 11529, Taiwan

  • Chih-Ta Chia

    • Department of Physics, National Taiwan Normal University, Taipei 106, Taiwan

  • Kung-Hsuan Lin

    • Institute of Physics, Academia Sinica, Taipei 11529, Taiwan