Non-collinear spin density wave in a two-dimensional Hubbard model

Abstract

For a wide range of band filling we study the spin density wave (SDW) states of the two dimensional Hubbard model on a square lattice within a mean-field approximation. We examine various self-consistent solutions with non-collinear spin texture including double-Q vortex lattice states and single-Q helical SDW states as well as soliton lattice states with collinear spin texture. The global phase diagram in n-U plane is presented. The vortex lattice states and the incommensurate helical SDW states which appear in the phase diagram show a rich variety of the self-consistent solutions of this model.