Effects of axial vorticity in elongated mixtures of Bose-Einstein condensates

We consider a meniscus between rotating and nonrotating species in the Bose-Einstein condensate with repulsive interatomic interactions, confined to a pipe-shaped trap. In this setting, we derive a system of coupled one-dimensional nonpolynomial Schrodinger equations for two mean-field wave functions. Using these equations, we analyze the phase separation and mixing in the pipe with periodic axial boundary conditions, i.e., in a toroidal configuration. We find that the onset of the mixing, in the form of suction, i.e., filling the empty core in the vortical component by its nonrotating counterpart, crucially depends on the vorticity of the first component and on the strengths of the interatomic interactions.