Publication: Soliton diffusion on the classical, isotropic Heinsenberg chain
Loading...
Identifiers
Publication date
2001-04
Defense date
Advisors
Tutors
Journal Title
Journal ISSN
Volume Title
Publisher
Springer
Impact
Export
Abstract
We investigate the di usive motion of a solitary wave on a classical, isotropic, ferromagnetic
Heisenberg spin chain with nearest-neighbour exchange interaction. The spins are coupled magnetically
to Gaussian white noise and are subject to Gilbert damping. The noise induces a collective, stochastic
time evolution of the solitary wave. Within a continuum version of the model we employ implicit collective
variables to describe this stochastic behaviour. Thermally excited magnons are disregarded. We derive
stochastic equations of motion for the collective variables and solve them numerically, in particular to obtain
their variances as functions of time. These results are compared to data from spin dynamics simulations
of a discrete chain. For some of the collective variables we nd good agreement with respect to the long
time behaviour, whereas for other variables the agreement is only qualitative; reasons for this are given.
For shorter times we derive analytical expressions for the variances of the collective variables, which also
agree well with spin dynamics.
Description
Keywords
Bibliographic citation
The European Physical Journal B, vol. 20, n. 3, apr. 2001. Pp. 405-417