Fig. 4.

Thickness-dependent Weyl orbit oscillations. a The MR of b-axis ribbon with different thicknesses. b The FFT spectra of b-axis ribbons with different thicknesses, in which the spectra are normalized with respect to the strongest frequency of electron pocket β. The Weyl orbit frequency almost vanishes in 40.6 nm thick ribbon. c Thickness dependence of the relative amplitude of the Weyl orbit oscillation and the bulk oscillation with respect to peak β. The thickness dependence of relative amplitude can be fitted by $e^{-L_0∕L}$, with L ₀ = 16.0 nm. The fitted value of L ₀ is in the same magnitude of the mean free path (c-axis) ~48.0 nm. The 20% error bar was added given to the FFT frequency spacing estimate. d The chiral-anomaly-induced negative MR in 40.6 nm thick b-axis ribbon