Fig. 4.

Position of the Hall crossover in the temperature-field phase diagram of YbRh₂Si₂. The crossover fields, B₀, are extracted from fits to R_H(B₂) of the crossed-field experiment, to of the single-field experiment, and to ρ(B₂) (cf. Materials and Methods). The values of the single-field Hall-effect experiment were scaled by 1/11 to account for the magnetic anisotropy of YbRh₂Si₂. The red horizontal bars reflect the FWHM at selected temperatures determined by the fit in Fig. 3, showing that the crossover fields of the various experiments and samples all lie within the range spanned by the FWHM. The dotted (dashed) line represents the boundary of the antiferromagnetic phase (Fermi-liquid regime) taken from ref. 13. Error bars are omitted in order to avoid confusion with the width of the crossover; with the exception of the data at 0.3 K and the single-field result of sample 2 at 0.19 K, the standard deviations are smaller than the symbol size.