Magnon Sidebands and Spin-Charge Coupling in Bismuth Ferrite Probed by Nonlinear Optical Spectroscopy

ORAL

Abstract

The interplay between spin waves (magnons) and electronic structure in materials leads to the creation of additional bands associated with electronic energy levels, called magnon sidebands which are difficult to probe due to their smaller energy scales (meV). Linear light absorption and scattering techniques at low temperatures are traditionally used to probe these sidebands. We show that optical second harmonic generation (SHG) can successfully probe the magnon sidebands at room temperature and up to 723K in bismuth ferrite, associated with large wave-vector multi-magnon excitations which linear absorption studies have thus far been unable to resolve. Polarized light studies and the temperature dependence of these sidebands reveal a spin-charge coupling interaction between the spontaneous polarization ($P_{s}$) and antiferromagnetic order parameter, $L$ in bismuth ferrite, that persists with short range correlation well into the paramagnetic phase.

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Authors

  • R. Ramesh

    University of California at Berkeley, University of California, Berkeley, CA, 94720, University of California-Berkeley, Department of Physics, and Material Science and Engineering, University of California, Berkeley, CA 94720, USA., Department of Physics, UC Berkeley, Dept. of Materials Science and Engineering, University of California, Berkeley, CA 94720

  • J. Orenstein

    Lawrence Berkeley National Laboratory and University of California Berkeley

  • J. Musfeldt

    University of Tennessee

  • V. Gopalan

    Pennsylvania State University, Materials Science and Engineering, Pennsylvania State University

  • Amit Kumar

    Pennsylvania State University, Materials Science and Engineering, Pennsylvania State University

  • M. Ramirez

  • S. Denev

    Pennsylvania State University, Materials Science and Engineering, Pennsylvania State University

  • N. Podraza

  • X. Xu

    University of Tennessee, Knoxville, University of Tennessee

  • R. Rai

  • Y-H. Chu

  • J. Seidel

    University of Califonia at Berkeley, UC Berkeley, UC Santa Barbara, University of Cambridge, FZ Dresden-Rossendorf, Germany, Oakridge National Lab, Lawrence Berkeley National Lab, TU Dresden, Germany, National Chiao Tung University, Taiwan, Department of Physics, and Material Science and Engineering, University of California, Berkeley, CA 94720, USA., Department of Physics, UC Berkeley

  • L. Martin

    University of Califonia at Berkeley, Department of Physics, and Material Science and Engineering, University of California, Berkeley, CA 94720, USA.

  • J. Ihlefeld

  • J. Klug

  • M. Bedzyk

  • O. Auciello

  • D. Schlom

    Cornell University, Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853; currently at Pennsylvania State University