Prog. Theor. Phys. Vol. 68 No. 6 (1982) pp. 1841-1853
Dynamics of Longitudinal Component in Ordered Spin Systems
Department of Physics, Nagoya University, Nagoya 464
*School of Mathematical and Physical Sciences, University of Sussex, Falmer, Brighton BN1 9QH
(Received July 5, 1982)
Dynamical behaviors of longitudinal component in the ordered planar and isotropic Heisenberg systems are examined in the hydrodynamical spin wave approximation. It is found that the long time behaviors are not subject to an exponential decay law in time which leads to a diffusive motion, but is represented by the inverse power law in time associated with the oscillation of spin wave frequency. Further investigations are done on effects due to spin wave damping, and we prove that the effects of this damping do not essentially after the long time behavior, that is, it is not reformed to diffusive motion. It is emphasized that the motion of longitudinal spin component is subject to non-Markov process.
DOI : 10.1143/PTP.68.1841
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