Nonlinear and nonreciprocal transport effects in untwinned thin films of ferromagnetic Weyl metal SrRuO<sub>3</sub>

ORAL

Abstract

In topological Dirac and Weyl semimetals, nontrivial conical bands with Fermi-arc surfaces states give rise to negative longitudinal magnetoresistance due to chiral anomaly effect and unusual thickness dependent quantum oscillation from Weyl-orbit effect, which were demonstrated recently in ferromagnetic Weyl metal SrRuO3 (SRO) thin films. In this work, we report the experimental observations of large nonlinear and nonreciprocal transport effects for both longitudinal and transverse channels in an untwinned Weyl metal of SRO thin film grown on a SrTiO3 substrate. From rigorous measurements with bias current applied along various directions with respect to the crystalline principal axes, the magnitude of nonlinear Hall signals from the transverse channel exhibits a simple sinα dependence at low temperatures, where α is the angle between bias current direction and orthorhombic [001]o, reaching a maximum when current is along orthorhombic [1-10]o. On the contrary, the magnitude of nonlinear and nonreciprocal signals in the longitudinal channel attains a maximum for bias current along [001]o, and it vanishes for bias current along [1-10]o. The observed α-dependent nonlinear and nonreciprocal signals in longitudinal and transverse channels reveal a magnetic Weyl phase with an effective Berry curvature dipole along [1-10]o, accompanied by 1D chiral edge modes along [001]o.

*This work was supported by the National Science and Technology Council of Taiwan (NSTC Grant No. 108-2628-M-001-007-MY3 and 111-2112-M-001-056-MY3)

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Publication: Kar et al. arXiv:2307.04482

Presenters

  • Wei-Li Lee

    • Inst. of Physics, Academia Sinica
    • Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan

Authors

  • Uddipta Kar

    • Inst. of Physics, Academia Sinica

  • Cho-Hao Lu

    • Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
    • Inst. of Physics, Academia Sinica

  • Akhilesh K Singh

    • Academia Sinica
    • Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
    • Inst. of Physics, Academia Sinica

  • P.V. Sreenivasa Reddy

    • Department of Physics, National Taiwan University, Taipei 10617, Taiwan
    • Dept. of Physics, National Taiwan University

  • Youngjoon Han

    • Dept. of Physics, California Institute of Technology

  • Xinwei Li

    • California Institute of Technology
    • Dept. of Physics, California Institute of Technology
    • Rice University

  • Cheng-Tung Cheng

    • Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan
    • Inst. of Physics, Academia Sinica

  • Song Yang

    • 2National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
    • Scientific Research Division, NSRRC, Hsinchu

  • Chun-Yen Lin

    • National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
    • Scientific Research Division, NSRRC, Hsinchu

  • Chia-Hung Hsu

    • National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
    • Scientific Research Division, NSRRC, Hsinchu
    • National Synchrotron Radiation Research Center

  • I-Chun Cheng

    • Graduate Institute of Photonics and Optoelectronics, National Taiwan University

  • David Hsieh

    • California Institute of Technology
    • Dept. of Physics, California Institute of Technology

  • Wei-Cheng Lee

    • Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, New York 13902, USA
    • Binghamton University

  • Guang-Yu Guo

    • Department of Physics
    • Department of Physics, National Taiwan University, Taipei 10617, Taiwan
    • Dept. of Physics, National Taiwan University
    • National Taiwan University

  • Wei-Li Lee

    • Inst. of Physics, Academia Sinica
    • Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan