Correlation studies in a spin imbalanced fermionic superfluid in presence of a harmonic trap

TL;DR

This paper studies the effects of a harmonic trap on a spin-imbalanced fermionic superfluid using the Hubbard model, focusing on correlation functions and the emergence of the FFLO phase.

Contribution

It provides a detailed analysis of how trapping potential influences correlation functions and the stability of the FFLO phase in spin-imbalanced fermionic superfluids.

Findings

Trap strength affects particle density and correlation functions.

FFLO phase appears with and without trap.

Large trapping depths lead to system depletion.

Abstract

We investigate different physical properties of a spin imbalanced fermionic superfluid described by an attractive Hubbard model in presence of a harmonic trap. To characterize the ground state of such a system, we compute various correlation functions, such as pairing, density and current correlations To underscore the effect of the trap, we compute these quantities as a function of strength of the trapping potential. A distinguishing feature of a superfluid state with population imbalance, is the appearance of a phase with spatially modulating gap function, called the Fulde- Ferrell-Larkin-Ovchinnikov (FFLO) phase which is present for both with and without trap. Trapping effects induce lowering of particle density and yields an empty system in the limit of large trapping depths.