title: Transverse spin-gradient functional for noncollinear spin-density-functional theory.
abstract: We present a novel functional for spin-density-functional theory aiming at the description of noncollinear magnetic structures. The construction of the functional employs the spin-spiral-wave state of the uniform electron gas as reference system. We show that the functional depends on transverse gradients of the spin magnetization; i.e., in contrast with the widely used local spin density approximation, the functional is sensitive to local changes of the direction of the spin magnetization. As a consequence the exchange-correlation magnetic field is not parallel to the spin magnetization and a local spin torque is present in the ground state of the Kohn-Sham system. As a proof of principle, we apply the functional to a Chromium monolayer in the noncollinear 120°-Néel state.
authors.affiliation: Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany and Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
authors.forename: F G
authors.initials: FG
authors.lastname: Eich
authors.forename: E K U
authors.initials: EK
authors.lastname: Gross