Two-component repulsive atomic Fermi gases in a thin spherical shell

TL;DR

This paper investigates the ground-state phases of two-component repulsive Fermi gases confined in a thin spherical shell, revealing phase transitions, effects of mass imbalance, and novel structures under rotation using a self-consistent Hartree-Fock approach.

Contribution

It introduces a detailed analysis of phase behavior and structural formations in spherical shell Fermi gases, including the impact of interactions, mass imbalance, and rotation, which were not previously explored in this context.

Findings

Identification of a miscible-immiscible transition controlled by interaction strength.

Discovery of three-chunk sandwich structures in rotating, mass-imbalanced mixtures.

Critical interaction strength decreases with mass ratio in imbalanced systems.

Abstract

We present possible ground-state structures of two-component atomic Fermi gases with repulsive interactions in a thin spherical shell geometry by implementing a self-consistent Hartree-Fock approximation. The system exhibits a miscible-immiscible transition from a homogeneous mixture to two-chunk phase separation as the interaction strength crosses a critical value. While the critical value is relatively insensitive to population imbalance for equal-mass mixtures, it decreases with the mass ratio when mass-imbalance is present. The interaction may be tuned by the two-body scattering length or the radius of the sphere, thereby allowing the system to cross the transition by varying different parameters. When the atoms on the sphere are rotating, three-chunk sandwich structures emerge in mass-imbalanced mixtures as a consequence of maximal angular momentum along the rotation axis. Some indications of geometric effects and possible experimental implications are also discussed.