Direct observation of Dirac nodal-line fermions in a mixed-anion superconductor HfP<sub>2-x</sub>Se<sub>x</sub>

ORAL

Abstract

In recent years, there has been an active exploration of materials for superconductors with Dirac nodal-line in their electronic structure. MSiCh (M=Zr, Hf; Ch=S,Se) is known as an ideal Dirac nodal-line semimetal with a Si square-net as a glide plane. It is then expected that the crystal structure of MSiCh can give us a hint for material exploration of nodal-line superconductors. Here we focus on a superconductor MP2-xChx, which is isostructural to MSiCh with a P-square net. Previously, we predicted and observed the nodal-line accompanied by fast Dirac particles in ZrP1.24Se0.57. In order to systematically understand the changes in electronic structure by different elements, we have performed an angle-resolved photoelectron spectroscopy of HfP1.48Se0.37 using synchrotron radiation. We have found the nodal-loop with the fastest Dirac velocity (1.3×106 m/s). Its origin and the effect of spin-orbit coupling will be discussed by comparing with the results of MSiS and ZrP1.24Se0.57 in terms of lattice constants and the energy of the elemental orbitals.

*ARPES measurement was performed at BL-1 of HiSOR (Proposal Nos. 21AG040, 21BG047). This work was financially supported by JSPS KAKENHI (Grant Nos. 17H06138, 18H03683, 20K03842)

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Presenters

  • Yukimi Nishioka

    • Graduate School of Advanced Science and Engineering, Hiroshima Univ.
    • Hiroshima University

Authors

  • Yukimi Nishioka

    • Graduate School of Advanced Science and Engineering, Hiroshima Univ.
    • Hiroshima University

  • Satoshi Ishizaka

    • Hiroshima University
    • Hiroshima Uviversity

  • Kenta Kuroda

    • Hiroshima University
    • Graduate School of Advanced Science and Engineering, Hiroshima Univ.
    • Hiroshima Univ

  • Akihiro Ino

    • Kurume Institute of Technology

  • Shiv Kumar

    • Hiroshima University

  • Kenya Shimada

    • Hiroshima University

  • Hijiri Kito

    • National Institute of Advanced Industrial Science and Technology

  • Izumi Hase

    • National Institute of Advanced Industrial Science and Technology

  • Shigeyuki Ishida

    • National Institute of Advanced Industrial Science and Technology
    • AIST
    • AIST, Tsukuba, Japan

  • Kunihiko Oka

    • National Institute of Advanced Industrial Science and Technology

  • Hiroshi Fujihisa

    • National Institute of Advanced Industrial Science and Technology

  • Yoshito Gotoh

    • National Institute of Advanced Industrial Science and Technology

  • Yoshiyuki Yoshida

    • National Institute of Advanced Industrial Science and Technology
    • AIST

  • Akira Iyo

    • National Institute of Advanced Industrial Science and Technology
    • AIST

  • Hiraku Ogino

    • National Institute of Advanced Industrial Science and Technology

  • Hiroshi Eisaki

    • Inst. of Advanced Industrial Science and Tech., Tsukuba, Ibaraki 305-8568, Japan.
    • National Institute of Advanced Industrial Science and Technology
    • Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan
    • AIST
    • Inst. of Advanced Industrial Science and Tech.
    • AIST, Tsukuba, Japan

  • Kenji Kawashima

    • IMRA JAPAN Co., Ltd.
    • IMRA JAPAN CO., LTD.

  • Yousuke Yanagi

    • IMRA JAPAN Co., Ltd.
    • IMRA JAPAN CO., LTD.

  • Akio Kimura

    • Graduate School of Advanced Science and Engineering, Hiroshima Univ.
    • Hiroshima Univ
    • Hiroshima University