Fig. 1: Data overview and characteristic transport and thermodynamic scales of Ce₃Bi₄Pd₃.

a Temperature-dependent electrical resistivity at various fixed magnetic fields. For B > 9 T, iso-B cuts (dots) were taken from panel (c). The zero-field resistivity of the nonmagnetic reference compound La₃Bi₄Pd₃ is shown for comparison. The small kink seen near 2.5 K in the zero-field data is associated with the onset of a giant spontaneous Hall voltage that, due to the large associated Hall angle, leaves an imprint also on the longitudinal resistivity¹¹. The low-field data are taken from Ref. 11. b Arrhenius plot of the linear response normal (antisymmetrized) Hall coefficient R_H of Ce₃Bi₄Pd₃ (black symbols). The black line is a guide to the eyes. Red and blue lines correspond to fits with \({R}_{{{{{{{{\rm{H}}}}}}}}}={R}_{{{{{{{{\rm{H,i}}}}}}}}}\exp [{E}_{{{{{{{{\rm{a}}}}}}}}}/({k}_{{{{{{{{\rm{B}}}}}}}}}T)]\), where n_i = 1/(R_H,ie) is the charge carrier concentration in a simple one-band model. Below 10 K, the data saturate to a constant value (dashed orange line), with the charge carrier concentration n₀ (again in a one-band model). c Magnetoresistance isotherms in fields up to B = 37 T, for various temperatures between 0.5 and 20 K. d Normal (antisymmetrized) Hall resistivity isotherms at the same fields and temperatures. B_c1 and B_c2 are determined in Fig. 2. Below \({B}_{{{{{{{{\rm{H}}}}}}}}}^{{{{{{{{\rm{odd}}}}}}}}}\) (shown for the 0.5 K data), the anomalous Hall contribution (grey shading) leads to a deviation from the initial linear-in-B normal Hall resistivity by more than 5%. e Even-in-field (symmetrized, see Supplementary Note 6) Hall resistivity isotherms at low temperatures and fields. Above \({B}_{{{{{{{{\rm{H}}}}}}}}}^{{{{{{{{\rm{even}}}}}}}}}\) (shown for the 0.4 K data) this Weyl-node derived signal drops to below 0.2, which is 5% of the maximum of the lowest-temperature isotherm (data from Ref. 11). f Temperature-dependent electronic specific heat coefficient (see Supplementary Note 5 for details) vs T² at various fixed fields (open symbols are from Ref. 12). Above T_C/T (shown for the 0 T data), the data deviate by more than 5% from the low-temperature ΔC/T = ΓT² fit, which represents the linear Weyl dispersion. The spurious low-field features in the low-temperature resistivity isotherms (Fig. 1c) are imprints of the large Hall contributions, caused by the current path redistribution due to the large Hall angle¹¹.