Fig. 3
From: Scaling of Yu-Shiba-Rusinov energies in the weak-coupling Kondo regime
Temperature and B-field dependence of the Kondo resonance. a Temperature evolution of the zero-energy resonance at B = 0.1 T, which quenches the superconductivity in the sample (50 mV, 200 pA, 500 μVrms). The spectra are offset for clarity. A split zero-energy resonance is observed. Orange (blue) lines are fits according to the third-order scattering model as described in refs. 15, 16 including (excluding) uniaxial magnetic anisotropy as determined in (e). b Evolution of the step-like feature around E F in an external B field parallel to the surface normal (5 mV, 200 pA, 50 μVrms). c, d Effective temperature T eff as extracted from fits like in (a) versus the experimental temperature T exp. Orange squares (blue stars) are from fits accounting for (disregarding) the axial anisotropy as determined in (e). e Step energies versus B. Energies are extracted from the dI/dV spectra in (b) by a least-squares fit with symmetric step functions. The gray line indicates the fit to a Spin Hamiltonian for S = 1 with uniaxial anisotropy: D = −0.33 ± 0.01 meV; g = 2.03 ± 0.07. All spectra were acquired with a normal metal Au tip. Error bars in c–e account for the standard error on the least-squares fit parameter
