Computer simulations of the fluctuational dynamics of a long-overlap Josephson junction in the frame of the sine-Gordon model with a white noise source have been performed. It has been demonstrated that for the case of constant critical current density the mean escape time (MET) increases with increasing junction length; and for homogeneous bias current distribution the MET tends to a constant, while for inhomogeneous current distribution the MET quickly decreases after approaching a few Josephson lengths. The mean voltage (measured in the noise-induced regime where the phase consequently jumps between neighboring potential minima) versus junction length behaves inversely in comparison with the MET.

• Received 29 November 2006

DOI:https://doi.org/10.1103/PhysRevB.76.024504