Finite temperature dynamics of vortices in the two dimensional anisotropic Heisenberg model T. Kamppeter, F. G. Mertens, A. Sánchez, A. R. Bishop, F. Domínguez-Adame and N. Grønbech-Jensen Eur. Phys. J. B, 7 4 (1999) 607-618 Published online: 15 February 1999 DOI: 10.1007/s100510050653