Langevin dynamics in magnetic disorder

This master thesis reports of two methods, both using Langevin dynamics to simulate the motion of a charged particle in a two-dimensional infinite sized randomly distributed magnetic field. One of the methods uses periodic boundary conditions to mimic the infinite field, while the other continously creates the field in front of the particle. Measurements of the magnetic friction from both these methods are carried out and discussed. Both methods give the same result for low velocities but differs significantly for high. A behavior that is explained though the periodic boundary conditions let the particles lock up in tracks and therefore can not mimic an infinite field. The non-periodic boundaries however, gives rise to measurements that to large extent agrees with prior analytic results in both the high and low velocity limit.Validerat; 20101217 (root