On the spin asymmetry of ground states in trapped two-component Fermi gases with repulsive interactions

TL;DR

This paper investigates how shell structure influences spin asymmetry in two-dimensional trapped fermionic gases with weak repulsive interactions, revealing differences from three-dimensional behavior.

Contribution

It demonstrates that in 2D, spin asymmetry arises primarily from shell effects, contrasting with 3D cases, and provides a simplified model aligning with Hartree-Fock results.

Findings

Spin asymmetry in 2D gases is shell-structure dependent.

A qualitative single-particle model explains the observed phenomena.

Results agree with Hartree-Fock and diagonalization methods.

Abstract

We examine the spin asymmetry of ground states for two-dimensional, harmonically trapped two-component gases of fermionic atoms at zero temperature with weakly repulsive short range interactions. Our main result is that, in contrast to the three-dimensional case, in two dimensions a non-trivial spin-asymmetric phase can only be caused by shell structure. A simple, qualitative description is given in terms of an approximate single particle model, comparing well to the standard results of Hartree-Fock or direct diagonalization methods.