TDDFT for spin waves in two-dimensional systems: orbital-based approximations

The collective dynamics of electrons with Dirac-like dispersions, such as in doped graphene, is not well described by the usual semilocal approximations of (TD)DFT, which are based on the traditional electron gas. Instead, we use orbital-based approximations, most notably the Singwi-Tosi-Land-Sjolander (STLS) approach, generalized to systems with noncollinear spin. We calculate spin-wave dispersions in magnetized two-dimensional systems of itinerant electrons.