Exploring dynamical magnetism with time-dependent density-functional theory: from spin fluctuations to Gilbert damping

Abstract

We use time-dependent spin-density-functional theory to study dynamical magnetic phenomena. First, we recall that the local-spin-density approximation (LSDA) fails to account correctly for magnetic fluctuations in the paramagnetic state of iron and other itinerant ferromagnets. Next, we construct a gradient-dependent density functional that does not suffer from this problem of the LSDA. This functional is then used to derive, for the first time, the phenomenological Gilbert equation of micromagnetics directly from time-dependent density-functional theory. Limitations and extensions of Gilbert damping are discussed on this basis, and some comparisons with phenomenological theories and experiments are made.

References in corpus (5)

• Enhanced Gilbert Damping in Thin Ferromagnetic Films
• Linear Response Calculations of Spin Fluctuations
• Magnons in real materials from density-functional theory
• Spin currents and spin dynamics in time-dependent density-functional theory
• A First-Principles Theory of Bloch Walls in Ferromagnets

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• Gilbert Damping in Conducting Ferromagnets I: Kohn-Sham Theory and Atomic-Scale Inhomogeneity
• The spin angular gradient approximation in the density functional theory
• Spin-density-functional theory: some open problems and application to inhomogeneous Heisenberg models
• Accessing long timescales in the relaxation dynamics of spins coupled to a conduction-electron system using absorbing boundary conditions
• Emergent Non-Abelian Gauge Theory in Coupled Spin-Electron Dynamics
• Landau-Lifshitz damping from Lindbladian dissipation in quantum magnets
• Microscopic theory of spin friction and dissipative spin dynamics