PHASE-LOCKED FLUXON-ANTIFLUXON STATES IN STACKED JOSEPHSON-JUNCTIONS

Measurements were made on a two-stack long Josephson junction with ver y similar parameters and electrical access to the thin middle electrod e. Mutually phase-locked fluxon-antifluxon states were observed. The o bserved propagation velocity is in agreement with the theoretical pred iction. The I-V curves recorded using the bias current in one of the j unctions as fixed parameter show that these states continue to also ex ist when the other junction is oppositely biased. This is found in num erical simulations based on the experimental junction parameters as we ll. We propose a model in which waves in the junctions coexist with fl uxons. (C) 1996 American Institute of Physics.