Abstract
The spin-wave relaxation mechanisms after intense laser excitation in ferromagnetic nickel films are investigated with all-optical pump-probe experiments. Uniform precession (Kittel mode), Damon-Eshbach surface modes and perpendicular standing spin waves can be identified by their dispersion . However, different to other ferromagnets deviates from the expected behavior. Namely, a mode discontinuity is observed that can be attributed to a nonlinear process. Above a critical field the power spectrum reveals a redistribution of the energy within the spin-wave spectrum populated.
- Received 22 June 2010
DOI:https://doi.org/10.1103/PhysRevB.82.134443
©2010 American Physical Society