Subharmonic self-locking of a Josephson soliton oscillator coupled to a resonator

Josephson soliton oscillators integrated in a resonator consisting of two closely spaced superconducting microstrips have been investigated experimentally. The dc IV-characteristic shows zero-field steps containing a number of resonator- induced substeps, occuring because of locking of the soliton oscillator to the resonator. The position of the substeps follows the structure of a "devil's staircase", and their appearance depends strongly on the externally applied dc magnetic field. © 1993.