Cd<sub>2</sub>Re<sub>2</sub>O<sub>7</sub>: a Strong Spin-Orbit Coupled Hund's Metal

ORAL

Abstract

A correlation-driven hidden order phase transition is found in a spin-orbit coupled pyrochlore metal Cd2Re2O7 (5d2) at 200 K. In this work, we use both first principle DFT+DMFT calculations and optical conductivity measurements to study the strong correlation effects in this material. The calculated optical conductivity by DFT+DMFT in the normal state at large spin-orbit coupling (SOC) and Hund's coupling shows incoherent feature which is consistent with the experimental results, while it shows coherent feature at small Hund's coupling. The DFT+DMFT calculations at large Hund's coupling perfectly reproduce the complete saturation behavior of resistivity observed experimentally in the normal state down to very low temperature, which indicates that the coherent energy scale in this material is largely decreased by both SOC and Hund's coupling. We also find clear orbital-selective behavior between jeff=1/2 and jeff=3/2 orbitals, which is a result of strong SOC and Hund's coupling.
These results indicate that the normal state of Cd2Re2O7 is a strong spin-orbit coupled Hund's metal. Furthermore, the measured optical conductivity in the hidden order phase shows spectral weight transfer to high frequency when decreasing temperature, which also indicates Hund's metal behavior.

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Presenters

  • Yilin Wang

    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory

Authors

  • Yilin Wang

    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory

  • Hu Miao

    • Brookhaven Natl Lab
    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory

  • Run Yang

    • Institute of Physics, Chinese Academy of Sciences
    • Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences
    • Institute of Physics, Chines Academy of Science

  • Youguo Shi

    • Insititute of Physics, Chinese Academy of Scienes (CAS)
    • Chinese Academy of Sciences
    • Chinese Academy of Scienes (CAS)
    • Institute of Physics,Chinese Academy of Scienes (CAS)
    • Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences
    • Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences

  • Christopher Homes

    • Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory
    • condense matter physic and material science, Brookhaven National Lab
    • CMPMS, Brookhaven Natl Lab

  • Gabriel Kotliar

    • CMPMS, Brookhaven national lab
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08856, USA
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • Rutgers University
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Lab
    • Physics and Astronomy Department, Rutgers University
    • Physics and Astronomy, rutgers university