Measured vs. Calculated Phonon Dispersions in the Cuprate HgBa<sub>2</sub>CuO<sub>4</sub>

ORAL

Abstract

Taking the prototypical high-Tc superconductor HgBa2CuO4 as an example, I will compare ab-initio density-functional-theory (DFT) calculations of the phonon dispersions to inelastic neutron scattering results that exhibit an anomaly in the Cu-O bond stretching branch. We have performed a series of calculations using several codes at different levels of approximation. Our results show good qualitative agreement for all codes, but only one gave a good quantitative agreement (better than 10%). All DFT calculations fail to reproduce the experimentally observed anomalous dispersion of the bond-stretching phonon branch. I will conclude my talk by mentioning other computational methods that may improve the agreement between the calculations and measurement.

*This work was supported by the DOE, Office of Basic Energy Sciences, Office of Science, under Contract No. DE-SC0006939. A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.

The work at UMN was funded by the Department of Energy through the UMN Center for Quantum Materials under DE-SC-
0016371.

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Presenters

  • Tyler Sterling

    • University of Colorado, Boulder

Authors

  • Irada Ahmadova

    • University of Colorado, Boulder

  • Tyler Sterling

    • University of Colorado, Boulder

  • Aaron Sokolik

    • University of Colorado, Boulder

  • Adrian Merritt

    • Physics, University of Colorado, Boulder
    • University of Colorado, Boulder

  • Douglas L Abernathy

    • Neutron Scattering Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Oak Ridge National Lab

  • Mun K. Chan

    • Los Alamos National Laboratory
    • Pulse Field Facility, National High Magnetic Field Laboratory, Los Alamos National Laboratory
    • National High Magnetic Field Laboratory, LANL
    • University of Minnesota
    • NHMFL

  • Yang Tang

    • University of Minnesota
    • Physics and Astronomy, University of Minnesota

  • Guichuan Yu

    • University of Minnesota

  • Martin Greven

    • School of Physics and Astronomy, University of Minnesota
    • University of Minnesota
    • Physics and Astronomy, University of Minnesota
    • School of Physics and Astronomy, University of Minnesota Twin Cities

  • Dmitry Reznik

    • University of Colorado, Boulder
    • University of Colorado at Boulder
    • Physics, University of Colorado, Boulder