Pseudo-gaps at the Mott quantum critical point in the perovskite rare earth nickelates

ORAL

Abstract

We explore the behavior of the pseudo-gap in the vicinity of the quantum critical point of charge transfer Mott insulators. We focus on NdNiO3 and LaNiO3, which as bulk material bracket the quantum critical point, but tune the nature of the transition in epitaxial ultra-thin films by substrate strain, film thickness and Nd/LaNiO3 composition. We expand our earlier work [1] that documented the energy gaps and pseudo gaps in thick films using tunneling spectroscopy between Al and nickelate films with 1nm Al2O3 barriers. We focus on the relative importance of disorder scattering and electron correlation in the pseudogaps. \\[4pt] [1] ``Gaps and pseudo-gaps at the Mott quantum critical point in the perovskite rare earth nickelates,'' S. James Allen, Adam J. Hauser, Evgeny Mikheev, Susanne Stemmer et al., arXiv:1404.2544.

*Supported by the MURI program of the ARO ``Emergent Phenomena at Complex Oxide Interfaces'' - Grant \# W911-NF-09-1-0398.

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Authors

  • S. James Allen

    • Univ of California - Santa Barbara

  • Adam Hauser

    • UC Santa Barbara

  • Evgeny Mikheev

    • Materials Department, University of California, Santa Barbara
    • UC Santa Barbara
    • Univ of California - Santa Barbara

  • Ankit Disa

    • Center for Research on Interface Structures and Phenomena and Department of Applied Physics, Yale University
    • Yale University

  • Fred Walker

    • Dept. of Applied Physics and Center for Research on Interface Structures and Phenomena, Yale University, New Haven, CT 06511, USA
    • Yale University
    • Center for Research on Interface Structures and Phenomena and Department of Applied Physics, Yale University
    • Yale Univ

  • Nelson Moreno

    • UC Santa Barbara

  • Charles Ahn

    • Dept. of Applied Physics and Center for Research on Interface Structures and Phenomena, Yale University, New Haven, CT 06511, USA
    • Yale University
    • Center for Research on Interface Structures and Phenomena and Department of Applied Physics, Yale University
    • Yale Univ

  • Leon Balents

    • Kavli Institute for Theoretical Physics - Univ of California - Santa Barbara
    • Kavli Institute of Theoretical Physics
    • Kavli Institute for Theoretical Physics
    • UC Santa Barbara

  • Susanne Stemmer

    • UC Santa Barbara

  • Susanne Stemmer

    • University of California, Santa Barbara
    • Materials Department, University of California, Santa Barbara
    • UC Santa Barbara
    • Materials Dept., Univ. of California, Santa Barbara
    • University of California Santa Barbara
    • Univ of California - Santa Barbara