Influence of nonlinear conductance andcosϕterm on the onset of chaos in Josephson junctions

Chaotic behavior in a Josephson junction is investigated. Threshold curves for the onset of chaos in the rf current-frequency plane are computed by means of Kolmogorov entropy. Both the nonlinear dependence of the quasiparticle current $I_N\mathrm{}\left(V\right)\mathrm{}$ and the $cos\varphi$ term have been considered to account for previously reported experimental results.