A classification of the ground states and topological defects in a rotating two-component Bose-Einstein condensate

TL;DR

This paper classifies the ground states and topological defects in a rotating two-component Bose-Einstein condensate, providing phase diagrams and analytical insights into various vortex structures and phase boundaries.

Contribution

It offers a comprehensive classification of ground states and topological defects in two-component BECs, including phase diagrams and analytical models without restrictions on component parameters.

Findings

Identified regions of coexistence, separation, and symmetry breaking.

Classified vortex lattice structures such as triangular and square coreless vortices.

Provided analytical justification using a non-linear sigma model.

Abstract

We classify the ground states and topological defects of a rotating two-component condensate when varying several parameters: the intracomponent coupling strengths, the intercomponent coupling strength and the particle numbers.No restriction is placed on the masses or trapping frequencies of the individual components. We present numerical phase diagrams which show the boundaries between the regions of coexistence, spatial separation and symmetry breaking. Defects such as triangular coreless vortex lattices, square coreless vortex lattices and giant skyrmions are classified. Various aspects of the phase diagrams are analytically justified thanks to a non-linear $\sigma$ model that describes the condensate in terms of the total density and a pseudo-spin representation.