Figure 5

Symbols: experimental dependencies of the normalized critical current and amplitudes of the first current steps for PC No. 1, plotted as \(i_n^{exp}(k \sqrt{P})=I_{n} (k \sqrt{P})/I_c (P = 0) \, (n=0,1,2)\). Lines: approximation of experimental dependencies obtained from the RSJ Eq. (1) with \(\Omega _{VAC}=0.35\). The solid blue one has been obtained for the current-phase relationship \(I_s=I_c \sin (\varphi )\), the dashed black one for \(I_s=I_c \sin (2\varphi )\). The x-axis for the dependencies \(i_n^{exp}(k \sqrt{P})\) and \(i_n^{calc-2 \varphi }(hi_{ac})\) was rescaled so that the first minima of \(i_1^{exp}(k \sqrt{P})\) and \(i_1^{calc-2 \varphi }(h i_{ac})\) coincide with the first minimum of \(i_1^{calc- \varphi }(i_{ac})\). The coefficients \(k=3.83\) and \(h=1.18\) were found for these two cases.