Spin waves in doped graphene with in-plane magnetic fields

Plasmonics in graphene is a subject of much current interest, with many prospects for novel applications. However, the dynamics of collective spin excitations and spin waves in graphene has been much less explored. Here, we study the spin-wave excitations of itinerant electrons in doped graphene in the presence of in-plane magnetic fields. We calculate the spin-wave dispersions using time-dependent density-functional methods within a standard tight-binding approach. We treat dynamical exchange-correlation effects using the STLS approach, generalized for systems with noncollinear spins.