DYNAMIC BEHAVIOR OF VORTICES IN THE CLASSICAL 2-DIMENSIONAL ANISOTROPIC HEISENBERG-MODEL

We use Monte Carlo and spin-dynamics simulation to study the vortex dy namics in the two-dimensional anisotropic Heisenberg model. We calcula ted the lifetime of vortex-antivortex pairs, the time needed for a vor tex to make a jump for one lattice spacing, the vortex density, the di stance between pairs as a function of temperature, and the energy of t he vortex core. Our results support the idea that a vortex does not mo ve through the lattice for long distances and a creation-annihilation process is a more adequate picture to describe its ''dynamics.''