Anharmonic Coupling in Beta Barium Borate Using Two-dimensional Spectroscopy.

ORAL

Abstract

High-field, ultrafast pulses of terahertz (THz) light allow the extreme excitation of atomic motion that allow us to probe regions of the underlying potential energy surface (PES). The PES, which dictates the material properties of a sample, has been studied with one-dimensional (1D, single pump pulse) measurements. At times, 1D measurements can be challenging to interpret. More information is available using 2D Terahertz spectroscopy to investigate the specific nonlinear couplings between excitations in solid materials. Here we use 2D Terahertz spectroscopy to gain insight into how phonon modes interact at large oscillation amplitudes to study $\beta $-barium borate (BBO), a commonly used nonlinear optical crystal. BBO has 16 phonon modes that are both Raman and IR active within our pump excitation bandwidth (1-6 THz), and the interaction between these modes leads to a feature rich 2D spectrum. We study the BBO sample responses, as a function of THz polarization with respect to the sample, to learn about the modes that nonlinearly interact to contribute to the 2D spectrum. Modeling the anharmonic coupling of the vibrational modes allows us to disentangle the 2D spectrum and gain insights into the complex underlying PES.~

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Authors

  • Megan Nielson

    Brigham Young University

  • John Spence

    Brigham Young University, Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, Department of Scientific Research, The Metropolitan Museum of Art, New York, NY 10028, Century Darkroom, Toronto, ON M4M 2S1, Canada, Colorado State University, University of Waterloo, Southern Connecticut State University, Clemson University, Oak Ridge National Laboratory, University of Bordeaux, BYU REU Program, New Mexico State University, Arizona State University, Biodesign Institute, Center for Applied Structural Discovery, University of Utah, University of Hawaii, Johns Hopkins University, Embry-Riddle Aeronautical University, Arizona State University, Utah State University, Department of Physics, United States Air Force Academy, Department of Chemistry, Case Western Reserve University, Air Force Research Laboratory, Wright-Patterson Air Force Base, United States Air Force Academy, Lousiana State University, Brigham Young University - Provo, The University of New Mexico, Department of Physics and Astronomy, Brigham Young University, SLAC National Accelerator Laboratory, Department of Chemistry, Brigham Young University, Department of Materials, Devices, and Energy Technologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA, Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003, USA, Center for Memory and Recording research, UCSD, Advanced Photon Source, Argonne National Laboratory, University of New Mexico, Los Alamos National Laboratory, University of Chicago

  • John Spence

    Brigham Young University, Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, Department of Scientific Research, The Metropolitan Museum of Art, New York, NY 10028, Century Darkroom, Toronto, ON M4M 2S1, Canada, Colorado State University, University of Waterloo, Southern Connecticut State University, Clemson University, Oak Ridge National Laboratory, University of Bordeaux, BYU REU Program, New Mexico State University, Arizona State University, Biodesign Institute, Center for Applied Structural Discovery, University of Utah, University of Hawaii, Johns Hopkins University, Embry-Riddle Aeronautical University, Arizona State University, Utah State University, Department of Physics, United States Air Force Academy, Department of Chemistry, Case Western Reserve University, Air Force Research Laboratory, Wright-Patterson Air Force Base, United States Air Force Academy, Lousiana State University, Brigham Young University - Provo, The University of New Mexico, Department of Physics and Astronomy, Brigham Young University, SLAC National Accelerator Laboratory, Department of Chemistry, Brigham Young University, Department of Materials, Devices, and Energy Technologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA, Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003, USA, Center for Memory and Recording research, UCSD, Advanced Photon Source, Argonne National Laboratory, University of New Mexico, Los Alamos National Laboratory, University of Chicago

  • John Spence

    Brigham Young University, Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, Department of Scientific Research, The Metropolitan Museum of Art, New York, NY 10028, Century Darkroom, Toronto, ON M4M 2S1, Canada, Colorado State University, University of Waterloo, Southern Connecticut State University, Clemson University, Oak Ridge National Laboratory, University of Bordeaux, BYU REU Program, New Mexico State University, Arizona State University, Biodesign Institute, Center for Applied Structural Discovery, University of Utah, University of Hawaii, Johns Hopkins University, Embry-Riddle Aeronautical University, Arizona State University, Utah State University, Department of Physics, United States Air Force Academy, Department of Chemistry, Case Western Reserve University, Air Force Research Laboratory, Wright-Patterson Air Force Base, United States Air Force Academy, Lousiana State University, Brigham Young University - Provo, The University of New Mexico, Department of Physics and Astronomy, Brigham Young University, SLAC National Accelerator Laboratory, Department of Chemistry, Brigham Young University, Department of Materials, Devices, and Energy Technologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA, Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003, USA, Center for Memory and Recording research, UCSD, Advanced Photon Source, Argonne National Laboratory, University of New Mexico, Los Alamos National Laboratory, University of Chicago

  • John Spence

    Brigham Young University, Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, Department of Scientific Research, The Metropolitan Museum of Art, New York, NY 10028, Century Darkroom, Toronto, ON M4M 2S1, Canada, Colorado State University, University of Waterloo, Southern Connecticut State University, Clemson University, Oak Ridge National Laboratory, University of Bordeaux, BYU REU Program, New Mexico State University, Arizona State University, Biodesign Institute, Center for Applied Structural Discovery, University of Utah, University of Hawaii, Johns Hopkins University, Embry-Riddle Aeronautical University, Arizona State University, Utah State University, Department of Physics, United States Air Force Academy, Department of Chemistry, Case Western Reserve University, Air Force Research Laboratory, Wright-Patterson Air Force Base, United States Air Force Academy, Lousiana State University, Brigham Young University - Provo, The University of New Mexico, Department of Physics and Astronomy, Brigham Young University, SLAC National Accelerator Laboratory, Department of Chemistry, Brigham Young University, Department of Materials, Devices, and Energy Technologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA, Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003, USA, Center for Memory and Recording research, UCSD, Advanced Photon Source, Argonne National Laboratory, University of New Mexico, Los Alamos National Laboratory, University of Chicago

  • John Spence

    Brigham Young University, Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, Department of Scientific Research, The Metropolitan Museum of Art, New York, NY 10028, Century Darkroom, Toronto, ON M4M 2S1, Canada, Colorado State University, University of Waterloo, Southern Connecticut State University, Clemson University, Oak Ridge National Laboratory, University of Bordeaux, BYU REU Program, New Mexico State University, Arizona State University, Biodesign Institute, Center for Applied Structural Discovery, University of Utah, University of Hawaii, Johns Hopkins University, Embry-Riddle Aeronautical University, Arizona State University, Utah State University, Department of Physics, United States Air Force Academy, Department of Chemistry, Case Western Reserve University, Air Force Research Laboratory, Wright-Patterson Air Force Base, United States Air Force Academy, Lousiana State University, Brigham Young University - Provo, The University of New Mexico, Department of Physics and Astronomy, Brigham Young University, SLAC National Accelerator Laboratory, Department of Chemistry, Brigham Young University, Department of Materials, Devices, and Energy Technologies, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA, Department of Physics, New Mexico State University, Las Cruces, New Mexico 88003, USA, Center for Memory and Recording research, UCSD, Advanced Photon Source, Argonne National Laboratory, University of New Mexico, Los Alamos National Laboratory, University of Chicago