Octahedral tilt driven Kondo lattice behavior with orbital-selective Mott transition of 4d Ca<sub>2-x</sub>Sr<sub>x</sub>RuO<sub>4</sub>

ORAL

Abstract

The physics of heavy fermion (HF) state, which manifests in f-electron system [1], begins to germinate in d-orbital system, for example, in 3d single-orbital van der Waals ferromagnet, transition metal oxide(TMO) LiV2O4 and multi-orbital Fe based family [2, 3, 4]. However, the existence of the HF state and its underlying mechanism remain to be questionable in 4d multi orbital systems. Using angle-resolved photoemission spectroscopy (ARPES), we observe the HF state in orbital-selective Mott phase (OSMP) of 4d TMO, Ca2-xSrxRuO4. Upon entering OSMP (x<0.5), we observe a massive spectral weight transfer, a 100meV-orbital selective gap for dxy-originated γ and corresponding change in dxz/yz-originated β band while dxz/yz-originated α band remains hardly changed. With the temperature drop across a characteristic temperature T*, spectral weight transfer gradually occurs from lower to higher binding energy in β and γ bands. This possible Kondo lattice behavior can be well explained by the key role of the octahedral tilt driven d-band hybridization. Our work firstly, demonstrates the possible origin of the formation of the HF state from 4d TMOs with structural distortions, which expands the boundary of the HF-candidates to the 4d multi orbital systems.

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Presenters

  • Minsoo Kim

    • Department of Physics and Astronomy, Seoul Natl Univ

Authors

  • Minsoo Kim

    • Department of Physics and Astronomy, Seoul Natl Univ

  • Junyoung Kwon

    • Physics, Seoul Natl Univ
    • Department of Physics and Astronomy, Seoul Natl Univ

  • Daun Chung

    • Department of Physics and Astronomy, Seoul Natl Univ

  • Younsik Kim

    • Department of Physics and Astronomy, Seoul Natl Univ
    • Seoul Natl Univ

  • Hanyoung Yoo

    • Physics and Astronomy, Seoul National University
    • Department of Physics and Astronomy, Seoul Natl Univ

  • Jongkeun Jung

    • Department of Physics and Astronomy, Seoul Natl Univ
    • Seoul Natl Univ

  • Beom Seo Kim

    • Physics, Seoul Natl Univ
    • Department of Physics and Astronomy, Seoul Natl Univ

  • Mi Kyung Kim

    • Department of Physics and Astronomy, Seoul Natl Univ

  • Jonathan Denlinger

    • Lawrence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Laboratory
    • Advanced Light Source, Lawrence Berkeley National Lab
    • Advanced Light Source
    • Advanced Light Source, E. O. Lawrence Berkeley National Laboratory

  • Moonsup Han

    • Department of Physics, University of Seoul

  • Takashi Mizokawa

    • Department of Applied Physics, Waseda University
    • School of Advanced Science and Engineering, Waseda University

  • yoshiyuki yoshida

    • National Institute of Advanced Industrial Science and Technology (AIST)
    • National Institute of Advanced Industrial Science and Technology

  • Wonshik Kyung

    • Physics, Seoul Natl Univ
    • Physics and Astronomy, Seoul National University
    • Department of Physics and Astronomy, Seoul Natl Univ
    • Seoul Natl Univ

  • Changyoung Kim

    • Physics, Seoul Natl Univ
    • Physics and Astronomy, Seoul National University
    • Department of Physics and Astronomy, Seoul National University
    • Department of Physics and Astronomy, Seoul Natl Univ
    • Seoul Natl Univ
    • Center for Correlated Electron Systems, Institute for Basic Science