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Relaxation time-scales and electron-phonon coupling in optically-pumped YBa<sub>2</sub>Cu<sub>3</sub>O<sub>6+x</sub> revealed by time-resolved Raman scattering

ORAL

Abstract

Quantum matter with striking properties has recently been generated by driving materials with ultrafast laser pulses. However, observing these phases by following a single property as a function of time after photoexcitation provides a limited picture. We directly tracked hot phonons and transient heating in a high temperature superconductor YBa2Cu3O6.9 by time-resolved Raman scattering with time-resolution of 220 fs. In addition, we used the hardening of the Raman-active apical oxygen phonon right after photoexcitation as an indirect probe of hot electrons, which equilibrated with hot phonons around 0.5 ps. Analysis based on the two-temperature model revealed temperature-independent electron-phonon coupling with λ ≈ 0.8 as well as significant anharmonicity that increased with temperature. It is essential to reduce this anharmonicity to generate longer lived nonequilibrium states in copper oxides. We will also discuss new insights into photoinduced superconductivity recently reported at lower doping that follow from these results.

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Presenters

  • Nick Pellatz

    University of Colorado, Boulder, Department of Physics, University of Colorado-Boulder

Authors

  • Nick Pellatz

    University of Colorado, Boulder, Department of Physics, University of Colorado-Boulder

  • Susmita Roy

    University of Colorado, Boulder, Department of Physics, University of Colorado, Boulder

  • Jungwoo Lee

    Materials Science and Engineering, University of Wisconsin-Madison, University of Wisconsin, Madison, Department of Materials Science and Engineering, University of Wisconsin-Madison,, University of Wisconsin, University of Wisconsin-Madison, University of Wisconsin-Maddison, Department of Materials Science and Engineering, University of Wisconsin-Madison

  • Jonathon Schad

    University of Wisconsin, Madison, University of Wisconsin Madison

  • Hom Kandel

    University of Wisconsin, Parkside, Physics, University of Wisconsin-Parkside

  • Nathan D Arndt

    University of Wisconsin, Parkside

  • Chang-Beom Eom

    Materials Science and Engineering, University of Wisconsin-Madison, University of Wisconsin, Madison, Department of Materials Science and Engineering, University of Wisconsin-Maddison, Department of Materials Science and Engineering, University of Wisconsin, Department of Materials Science Engineering, University of Wisconsin-Madison, Department of Materials Science and Engineering, University of Wisconsin-Madison,, University of Wisconsin, Material Science and Engineering, University of Wisconsin-Madison, University of Wisconsin-Madison, University of Wisconsin-Maddison, University of Wisconsin - Madison, University of Wisconsin Madison, Department of Materials Science and Engineering, University of Wisconsin-Madison

  • Dmitry Reznik

    University of Colorado, Boulder, Department of Physics, University of Colorado-Boulder, Department of Physics, University of Colorado, Boulder