CHAOTIC AND BALLISTIC DYNAMICS FOR 2-DIMENSIONAL ELECTRONS IN PERIODIC MAGNETIC-FIELDS

We investigate the classical properties of electrons moving in a super position of a uniform and periodically oscillating magnetic field. The most interesting dynamics occurs in the case where the uniform, and p eriodic fields are of comparable order of magnitude and the periodic c omponent originates from a planar arrangement of spins. For small ener gies almost the complete phase space is regular. With increasing energ y the fraction of irregular orbits increases and eventually the phase space becomes completely chaotic. For higher energies we observe the a ppearance of a ballistic mode which allows the electrons to travel wit h high velocity through the magnetized spin lattice. This regular ball istic mode might be of relevance for transport processes in solid-stat e physics.