Experimental observation on Jeff=1/2 state in CuAl2O4

ORAL

Abstract

The spin-orbit entangled pseudo-spin state, Jeff=1/2 has driven intriguing phenomena such as high-Tc superconductivity, quantum spin liquid, and topological semimetal. This studies have been conducted on 4d or 5d compounds but 3d systems haven't been focused on. The Jeff=1/2 states in 3d systems including cuprates haven't been considered to emerge in condensed matter physics. One reason is the spin-orbit coupling constant of 3d is smaller than that of Ru (4d) or Ir (5d) ions and the other is that many 3d systems have distorted-crystal structures which lead quenched orbital angular momentum. However, we suggest CuAl2O4 is a candidate material to induce Jeff=1/2 states. Cubic symmetry of the crystal structure verified by single crystal XRD supports Jeff=1/2 nature. Moreover, X-ray absorption spectroscopy also shows this nature following the electric dipole selection rule.

*Center for Correlated Electron Systems, Institute for Basic Science (IBS)

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Presenters

  • Hwanbeom Cho

    • Center for Correlated Electron Systems, Institute for Basic Science & Seoul National Univeristy
    • Department of Physics and Astronomy, Seoul National University (SNU)
    • Department of Physics and Astronomy, Seoul National University

Authors

  • Hwanbeom Cho

    • Center for Correlated Electron Systems, Institute for Basic Science & Seoul National Univeristy
    • Department of Physics and Astronomy, Seoul National University (SNU)
    • Department of Physics and Astronomy, Seoul National University

  • Choong Hyun Kim

    • Center for Correlated Electron Systems, Institute for Basic Science & Seoul National Univeristy
    • Center for Correlated Electron Systems, Institute for Basic Science
    • Department of Physics and Astronomy, Seoul National University
    • Seoul National University
    • CCES-IBS

  • Ara Go

    • Center for Theoretical Physics of Complex Systems, Institute for Basic Science
    • Institute for Basic Science
    • Center for Theoretical Physics of Complex Systems, Institute for Basic Science (IBS)

  • Hosub Jin

    • Ulsan National Institute of Science and Technology
    • Department of Physics, Ulsan National Institute of Science and Technology (UNIST)

  • Je-Guen Park

    • Department of Physics and Astronomy, Seoul National University
    • Center for Correlated Electron Systems, Institute for Basic Science & Seoul National Univeristy
    • 2 Center for Correlated Electron Systems, institute for Basic Science; and 3 Department of Physics and Astronomy ,Seoul National University, Seoul, South Korea
    • Department of Physics and Astronomy, Seoul National University (SNU)
    • Seoul National University
    • Department of Physics & Astronomy, Seoul National University, Seoul, Korea
    • Center for Correlated Electron Systems, Institute for Basic Science (IBS), Korea