Spinwave damping in the two-dimensional ferromagnetic XY model

Details Spinwave damping in the two-dimensional ferromagnetic XY model Spinwave damping in the two-dimensional ferromagnetic XY model

1999-12-14

arxiv.org/abs/cond-mat/9912241v1

Physics

Condensed Matter

Materials Science

20 two-column pages

Scientific paper

10.1103/PhysRevB.62.11585

The effect of damping of spinwaves in a two-dimensional classical ferromagnetic XY model is considered. The damping rate $\Gamma_{q}$ is calculated using the leading diagrams due to the quartic-order deviations from the harmonic spin Hamiltonian. The resulting four-dimensional integrals are evaluated by extending the techniques developed by Gilat and others for spectral density types of integrals. $\Gamma_{q}$ is included into the memory function formalism due to Reiter and Solander, and Menezes, to determine the dynamic structure function $S(q,\omega)$. For the infinite sized system, the memory function approach is found to give non-divergent spinwave peaks, and a smooth nonzero background intensity (``plateau'' or distributed intensity) for the whole range of frequencies below the spinwave peak. The background amplitude relative to the spinwave peak rises with temperature, and eventually becomes higher than the spinwave peak, where it appears as a central peak. For finite-sized systems, there are multiple sequences of weak peaks on both sides of the spinwave peaks whose number and positions depend on the system size and wavevector in integer units of $2\pi/L$. These dynamical finite size effects are explained in the memory function analysis as due to either spinwave difference processes below the spinwave peak or sum processes above the spinwave peak. These features are also found in classical Monte Carlo -- Spin-Dynamics simulations.

Affiliated with

Also associated with

No associations

Rating

Spinwave damping in the two-dimensional ferromagnetic XY model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Spinwave damping in the two-dimensional ferromagnetic XY model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spinwave damping in the two-dimensional ferromagnetic XY model will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-430467