Charge transfer in iridate-nickelate superlattices

ORAL

Abstract

The construction of superlattices, unit-cell-scale layering of two or more materials at the nanoscale, allows one to access novel properties not possessed by the constituent materials. Here, we show that in superlattices consisting of strontium iridate and lanthanum nickelate, up to one electron can transfer from iridium to nickel at the interfaces, leading to Ni2(d8) and the unusual oxidation state Ir5+(d4). Using density functional theory based calculations including a Hubbard U correction and spin-orbit coupling, we characterize the 1:1 superlattices with both (001) and (111) ordering, allowing us to explore the competition among Hund's coupling, the crystal field splitting and spin-orbit coupling. We find that the spin-orbit coupling present for iridium does not completely dominate the d4 configuration, which would result in a nonmagnetic state with a filled Jeff=3/2 manifold, but competes with the Hund's coupling and crystal field splitting. In these superlattices, the surprising competition in the energy landscape results in Ir5+ with a non-zero magnetic moment.

*The authors acknowledge funsing from ONR grant N000014-17-1-2770 and NSF grant DMR-1629059, as well as computational support from the DOD High Performance Computing Modernization Program for computational resources.

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Presenters

  • Michele Kotiuga

    • Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University, New Brunswick, THEOS, EPFL, Lausanne, Switzerland

Authors

  • Michele Kotiuga

    • Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University, New Brunswick, THEOS, EPFL, Lausanne, Switzerland

  • Heung-Sik Kim

    • Department of Physics, Kangwon National University
    • Department of Physics and Astronomy, Rutgers University; Kangwon National University, Chuncheon, Korea
    • Physics, Kangwon National University

  • David Vanderbilt

    • Department of Physics and Astronomy, Piscataway, NJ 08854, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ, USA
    • Department of Physics & Astronomy, Rutgers University
    • Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
    • Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, United States
    • Rutgers University
    • Physics, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, New Brunswick
    • Rutgers University, New Brunswick

  • Karin M Rabe

    • Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ, USA
    • Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
    • Dept. of Physics and Astronomy, Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University, Piscataway, NJ, United States
    • Department of Physics and Astronomy, Rutgers University, New Brunswick