2018/09/25 by D. M. Edwards, Edwards, D. M.
Chemistry · Materials Science · Physics and Astronomy · #Advanced NMR Techniques and Applications #FOS: Physical sciences #Magnetic Properties and Applications #Magnetic properties of thin films #Materials Science (cond-mat.mtrl-sci)
paper · pdf · doi:10.48550/arxiv.1809.09429
openalex publication_date 2018/09/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
There is a widely-held belief amongst theoreticians that the Gilbert damping parameter α in magnetization dynamics is infinite for a pure metal at T=0. The basic error leading to this belief is pointed out explicitly and the various methods of calculation used are viewed in a unified way based on the Lorentzian lineshape of ferromagnetic resonance spectra. A general torque formula for α is proposed as a good starting-point for treating inhomogeneous materials such as alloys, compounds and layered structures. Local spin density functional theory provides a simple physical picture, in terms of a non-uniform precessional cone angle in ferromagnetic resonance, of how such inhomogeneity contributes to the damping. In a complementary many-body theory this contribution is given by a vertex correction to the torque-torque response function.