Chaos in long Josephson junctions without external rf driving force

Simulations of long Josephson junctions in an external magnetic field show a variety of chaotic behaviors. They consist of period-doubling bifurcation, intermittency between and within Fiske steps, and quasiperiodic motion at Fiske steps. A physical explanation for the chaotic behavior is presented. The influence of surface resistance to the chaotic motion is investigated. A diagram in terms of dissipation and magnetic field is constructed to show where chaos occurs for a long junction.