In-medium bound-state formation and inhomogeneous condensation in Fermi gases in a hard-wall box

TL;DR

This paper investigates bound-state formation and inhomogeneous superfluid phases in imbalanced ultracold Fermi gases confined in a hard-wall box, providing insights into experimental realization of exotic quantum states.

Contribution

It analyzes how finite-size effects influence bound states and inhomogeneous phases, suggesting hard-wall traps are suitable for studying these phenomena.

Findings

Finite center-of-mass momentum bound states depend on imbalance parameters.

Hard-wall box does not significantly alter the many-body phase diagram.

Hard-wall traps are promising for experimental exploration of inhomogeneous superfluidity.

Abstract

The formation of bosonic bound states underlies the formation of a superfluid ground state in the many-body phase diagram of ultracold Fermi gases. We study bound-state formation in a spin- and mass-imbalanced ultracold Fermi gas confined in a box with hard-wall boundary conditions. Because of the presence of finite Fermi spheres, the center-of-mass momentum of the potentially formed bound states can be finite, depending on the parameters controlling mass and spin imbalance as well as the coupling strength. We exploit this observation to estimate the potential location of inhomogeneous phases in the many-body phase diagram as a function of spin- and mass imbalance as well as the box size. Our results suggest that a hard-wall box does not alter substantially the many-body phase diagram calculated in the thermodynamic limit. Therefore, such a box may serve as an ideal trap potential to bring experiment and theory closely together and facilitate the search for exotic inhomogeneous ground states.