2006/01/25 by Andrew L. Goodwin, Goodwin, Andrew L., Martin T. Dove +5
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic properties of thin films #Nonlinear Dynamics and Pattern Formation #Other Condensed Matter (cond-mat.other) #Theoretical and Computational Physics #cond-mat.other
paper · pdf · doi:10.48550/arxiv.cond-mat/0601559
10 pages, 1 figure
openalex publication_date 2006/01/25 · arxiv created 2006/06/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A model-independent approach capable of extracting spin-wave frequencies and displacement vectors from ensembles of supercell spin configurations is presented. The method is appropriate for those systems whose spin-dynamical motion is well characterised by small-amplitude fluctuations that give harmonic spin waves. First, the the spin-dynamical matrix is described and its eigenvalues shown to correspond to the spin-wave mode frequencies. The generalised spin coordinate matrix - a quantity that may be calculated from the observed spin orientations in an ensemble of spin configurations - is then introduced and its relationship to the spin-dynamical matrix established. Its eigenvalues are subsequently shown to be related to the spin-wave mode frequencies, allowing the extraction of spin-wave dispersion curves from configurational ensembles. Finally, a quantum-mechanical derivation of the same results is given, and the method applied as a case study to spin Monte-Carlo configurations of a 3D Heisenberg ferromagnet.