npj Quantum Materials (Jan 2023)

The thickness dependence of quantum oscillations in ferromagnetic Weyl metal SrRuO3

  • Uddipta Kar,
  • Akhilesh Kr. Singh,
  • Yu-Te Hsu,
  • Chih-Yu Lin,
  • Bipul Das,
  • Cheng-Tung Cheng,
  • M. Berben,
  • Song Yang,
  • Chun-Yen Lin,
  • Chia-Hung Hsu,
  • S. Wiedmann,
  • Wei-Cheng Lee,
  • Wei-Li Lee

DOI
https://doi.org/10.1038/s41535-023-00540-3
Journal volume & issue
Vol. 8, no. 1
pp. 1 – 10

Abstract

Read online

Abstract In a thin Weyl semimetal, a thickness dependent Weyl-orbit quantum oscillation was proposed to exist, originating from a nonlocal cyclotron orbit via electron tunnelings between top and bottom Fermi-arc surface states. Here, magneto-transport measurements were carried out on untwinned Weyl metal SrRuO3 thin films. In particular, quantum oscillations with a frequency F s1 ≈ 30 T were identified, corresponding to a small Fermi pocket with a light effective mass. Its oscillation amplitude appears to be at maximum for thicknesses in a range of 10 to 20 nm, and the phase of oscillation exhibits a systematic change with film thickness. The constructed Landau fan diagram shows an unusual concave downward curvature in the 1/μ 0 H n -n curve, where n is the Landau level index. From thickness and field-orientation dependence, the F s1 oscillation is attributed to be of surface origin. Those findings can be understood within the framework of the Weyl-orbit quantum oscillation effect with non-adiabatic corrections.