Flux flow steps are experimentally found in a triangular cell of long Josep
hson junctions that we successfully fabricated. Their behavior at the relev
ant values of the magnetic flux linked to the cell (Phi = 0 and Phi = Phi(0
)/2) is compared with the one predicted by numerical simulations of the cou
pled sine-Gordon equations that model the system. Qualitative agreement bet
ween numerical and experimental results is found. (C) 1999 American Institu
te of Physics. [S0003-6951(99)02601-7].