  Time-dependent spin phenomena in condensed matter are most often either
described in the weakly correlated limit of metallic Stoner/Slater-like
magnetism via band theory or in the strongly correlated limit of
Heisenberg-like interacting spins in an insulator. However many experimental
studies, e.g. of (de)magnetization processes, focus on itinerant local-moment
materials such as transition metals and various of their compounds. We here
present a general theoretical framework that is capable of addressing
correlated spin dynamics, also in the presence of a vanishing charge gap. A
real-space implementation of the time-dependent rotational-invariant slave
boson methodology allows to treat non-equilibrium spins numerically fast and
efficiently beyond linear response as well as beyond the band-theoretical or
Heisenberg limit.
