Nonlinear waves in one-dimensional classical helimagnets (including ferromagnets and antiferromagnets) with easy planes in the absence of external fields are studied in the continuum description. Using the reductive perturbation method, we derive a Korteweg-de Vries (KdV) equation for an ordinary helimagnet and a modified KdV equation for an exceptional one. These equations have gapless-soliton solutions.
Progress of Theoretical Physics
- Pub Date:
- June 1981