Breakdown of the spin-orbit imposed Jeff $=$ 0 singlet state in double-perovskite iridates with Ir5$+$(5d4) ions

ORAL

Abstract

The strong spin-orbit interaction is expected to impose a nonmagnetic singlet ground state, Jeff $=$ 0, in iridates having pentavalent Ir5$+$(5d4) ions. We report an exotic magnetic ground state in single-crystal double-perovskite Ba2YIrO6 and Sr doped Ba2YIrO6 with Ir5$+$(5d4) ions. The magnetic state fits no descriptions of the spin-alone S$=$1 state in materials with d4 ions as well as the Jeff $=$ 0 singlet state but appears to be situated intermediate between them. The emergence of the magnetic ground state is extraordinary because its occurrence contradicts the highly anticipated Jeff $=$ 0 singlet ground state in presence of the strong spin-orbit interaction and highlights the unusual interplay between the strong spin-orbit interaction, electron-electron correlations and electron hopping.

*This work was supported by the US National Science Foundation via grants DMR- 1265162 and DMR-1600057, and the Department of Energy (BES) through grant No. DE- FG02-98ER45707 (PS)

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Authors

  • Jasminka Terzic

    • Department of Physics and Astronomy and Center for Advanced Materials University of Kentucky, KY

  • Hao Zheng

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

  • Feng Ye

    • Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN

  • Pedro Schlottmann

    • Department of Physics, Florida State University, Tallahassee, FL

  • Hengdi Zhao

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

  • Shujuan Yuan

    • Department of Physics and Astronomy and Center for Advanced Materials University of Kentucky, KY

  • Gang Cao

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