title: Spin dynamics from time-dependent spin-density-functional theory.
abstract: We derive the spin-wave dynamics of a magnetic material from the time-dependent spin-density-functional theory in the linear response regime. The equation of motion for the magnetization includes, besides the static spin stiffness, a "Berry curvature" correction and a damping term. A gradient expansion scheme based on the homogeneous spin-polarized electron gas is proposed for the latter two quantities, and the first few coefficients of the expansion are calculated to second order in the Coulomb interaction.
authors.affiliation: Department of Physics, University of Missouri, Columbia, Missouri 65211, USA.
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Qian
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vignale