Bond stretching branch dispersions in undoped La<sub>2</sub>CuO<sub>4</sub> calculated using LDA+U

ORAL

Abstract

In undoped, insulating La2CuO4 (LCO), the longitudinal Cu-O bond-stretching branches are observed to be nearly dispersionless. As doping increases, these branches soften away from the zone center and disperse downwards towards the zone boundary. LDA calculations, which predict the undoped cuprates to be metallic, do not find the nearly dispersionless character of these modes. In the LDA, these branches disperse downward towards the zone boundary as in overdoped metallic LCO. In this work, we employ the Hubbard-U correction in the LDA+U method to calculate the dispersions for a range of U values. With U=6 eV, we find the insulating, antiferromagnetic ground state of LCO. Our calculations predict the bond-stretching modes to be nearly dispersionless in the insulating ground state in agreement with experiment.

*This work was supported by the DOE, Office of Basic Energy Sciences, Office of Science, under Contract No. DE-SC0006939. A portion of the research was performed using computational resources sponsored by the Department of Energy's Office of Energy Efficiency and Renewable Energy and located at the National Renewable Energy Laboratory.

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Presenters

  • Tyler Sterling

    • University of Colorado, Boulder

Authors

  • Tyler Sterling

    • University of Colorado, Boulder

  • Aaron M Holder

    • National Renewable Energy Laboratory

  • Dmitry Reznik

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