Unvortex lattice and topological defects in rigidly rotating multicomponent superfluids

Abstract

By examining rotating ferromagnetic spinor condensates through the perspective of large spin, we identify a novel type of topological point defects in the magnetization texture. These defects are not predicted by conventional homotopy analysis but rather by the Riemann-Hurwitz formula. The magnetization texture in the system is described by an equal-area mapping from the plane to the sphere of magnetization, forming a lattice of uniformly charged Skyrmions. This lattice contains doubly-quantized (winding number = 2) point defects arranged on the sphere in a tetrahedral configuration. The fluid found to be rotating rigidly, except at the point defects, where the vorticity vanishes. This vorticity structure describes an unconventional "unvortex" lattice, which contrasts with the well-known vortex lattice in scalar rotating superfluids, where vorticity is concentrated exclusively within defect points. Numerical results are presented, confirming these predictions and demonstrating their persistence in smaller-spin condensates