Numerical calculation of the energy barrier distribution in disordered many-particle systems: the path integral method

We present a numerical method for the evaluation of the distribution of energy barriers between metastable states in many-particle systems with arbitrary interparticle interaction. The method is based on the search for the optimal path between the two given metastable states using the minimization of the corresponding action occurring in the Onsager-Machlup functional for the transition probability between these two slates. Test results for a non-interacting system of magnetic particles and for a dipolar magnetic glass are reported. (C) 1998 Elsevier Science B.V. All rights reserved.