Dynamics of interacting wires

The technique of coupled map lattices is applied to investigate the time dependence of magnetization of a set of bistable wires. Subsequent moments of time t(k), between which the mapping is performed, are chosen when a domain wall within a wire starts to move or stops. Iterative maps are formed by means of the integration of the equations of motion of the domain walls. The system is proved to be piecewisely integrable, and it does not exhibit chaos in long time limit. However, the Lyapunov exponent determined numerically is positive during a transient time. For small amplitude of the applied magnetic field, more than one limit cycle is found. Observed random long-time behaviour can be assigned to thermal fluctuations of the switching field, which shift a trajectory from one limit cycle to another one. We show also some experimental results on the hysteresis loops of Fe77.5B15Si7.5 and on the fluctuation distribution of the switching field. (C) 2002 Elsevier Science B.V. All rights reserved.