Spontaneous Vortex Lattices in Quasi 2D Dipolar Spinor Condensates

TL;DR

This paper investigates the formation and behavior of vortex lattices in quasi-2D dipolar spinor condensates, revealing how dipolar interactions and magnetic fields influence spin textures and equilibrium states.

Contribution

It introduces the first detailed analysis of vortex lattice configurations and spin textures in quasi-2D dipolar condensates under varying magnetic fields.

Findings

Dipolar energy induces a vortex lattice with alternating spin orientations.

Large magnetic fields lead to long-lived dynamical states with elliptic and hyperbolic spin textures.

The true equilibrium state is a uniaxial spin density wave with a specific wavelength.

Abstract

Motivated by recent experiments\cite{BA}\cite{BB}, we study quasi 2D ferromagnetic condensates with various aspect ratios. We find that in zero magnetic field, dipolar energy generates a local energy minimum with all the spins lie in the 2D plane forming a row of {\em circular} spin textures with {\em alternating} orientation, corresponding to a packing of vortices of {\em identical} vorticity in different spin components. In a large magnetic field, the system can fall into a long lived dynamical state consisting of an array of elliptic and hyperbolic Mermin-Ho spin textures, while the true equilibrium is an uniaxial spin density wave with a single wave-vector along the magnetic field, and a wavelength similar to the characteristic length of the long lived vortex array state.