Fig. 3

Josephson inductance extracted from RF and DC measurements. a Schematic representation of L_j and its relation to the CPR of a Josephson junction. L_j can be understood as the slope of the current-phase relation around zero phase bias. b Schematic representation of L_j extraction from the cavity resonance frequency. The potential energy near ϕ = 0 is harmonic, with the fundamental frequency given by the junction inductance L_j and the cavity capacitance C and inductance L_g as \(\omega = 1{\mathrm{/}}\sqrt {\left( {L_{\mathrm{j}} + L_{\mathrm{g}}} \right)C}\). c Comparison of Josephson inductance L_j extracted from DC measurements (black) and from the microwave measurements (blue). We attribute differences to deviations from a sinusoidal current-phase relation (see main text for details). The error band from our fit of L_j can be found in Supplementary Fig. 4