We consider DC-biased arrays of overdamped Josephson junctions with differe
nt lattice geometries, and demonstrate that, with suitable choice of bias c
urrents, it is possible for the in-phase state of the array to exhibit so-c
alled "neutral stability". This extends the finding of Wiesenfeld et al. (J
. Appl. Phys. 76 (1994) 3835) for two-dimensional rectangular lattices to a
rbitrary lattice types. (C) 2001 Published by Elsevier Science B.V.