DIFFUSION, RELAXATION, AND RESPONSE FUNCTIONS OF SOLITONS IN ONE-DIMENSIONAL ANTIFERROMAGNETS

Two mechanisms of diffusive kink motion in a quasi-one-dimensional rhombic antiferromagnet, placed in an external magnetic field, are considered, together with their effect on the soliton central peak in the dynamic structure factor (DSF). The temperature and field dependence of the diffusion coefficients is calculated. It is shown that non-dissipative diffusion gives zero contribution to the DSF, while ordinary Einstein diffusion changes its form considerably in the region of small wavevectors.