Phase separation in a mixture of trapped charged Bose-Einstein condensates

TL;DR

This paper investigates phase separation configurations and rotational behaviors of charged Bose-Einstein condensate mixtures in different geometries under magnetic fields, revealing how interactions and geometry influence phase and flow properties.

Contribution

It provides a comparative analysis of azimuthal and radial phase separation in charged BEC mixtures, highlighting the effects of interactions and trap shape on phase transitions and rotational dynamics.

Findings

Azimuthal phase separation is favored in equal interaction mixtures.

Radial phase separation occurs with interaction imbalance and depends on trap shape.

Quantization of circulation breaks down in azimuthal phase separation.

Abstract

We study the phase separation configurations and their rotational properties for a mixture of two interacting charged Bose-Einstein condensates subject to a magnetic field trapped in disc and Corbino geometries. We calculate the ground state energies of azimuthal and radial phase separation configurations using the Gross-Pitaevskii and the Thomas-Fermi approximations. We show that the results for experimentally relevant system parameters from both approaches are in good agreement. The immiscible mixture in both geometries with equal intracomponent interactions favors the azimuthal phase separation for all intercomponent interactions. Only an imbalance in the intracomponent interactions can result in a transition to the radial phase separation, for which the transition becomes sensitive to the shape of the trap. We present phase diagrams as a function of the inter and intracomponent interactions. While the radial phase separation is widely favoured in disc geometry, the azimuthal phase separation is favoured for narrower Corbino geometries. We explore the rotational properties of the spatially separated condensates under the magnetic field, studying their angular momenta and velocity fields. The quantization of circulation breaks down for the azimuthal phase separation. In this case, the bulk region of the condensate continues to display superfluid flow behavior whereas the velocity field shows a rigid body behavior along the phase boundaries.