Neutral skyrmion configurations in the low-energy effective theory of spinor-condensate ferromagnets

Abstract

We study the low-energy effective theory of spinor condensate ferromagnets for the superfluid velocity and magnetization degrees of freedom. This effective theory describes the competition between spin stiffness and a long-range interaction between skyrmions, topological objects familiar from the theory of ordinary ferromagnets. We find exact solutions to the nonlinear equations of motion describing neutral configurations of skyrmions and antiskyrmions. These analytical solutions provide a simple physical picture for the origin of crystalline magnetic order in spinor condensate ferromagnets with dipolar interactions. We also point out the connections to effective theories for quantum Hall ferromagnets.