Many-body molecule formation at a domain wall in a one-dimensional strongly interacting ultracold Fermi gas

TL;DR

This paper investigates how bound states influence the dynamics and phase separation in a strongly interacting one-dimensional ultracold Fermi gas, revealing the emergence of pairing correlations at domain walls.

Contribution

It provides a full many-body numerical analysis showing the formation of molecules at domain walls and their role in stabilizing phase separation in 1D Fermi gases.

Findings

Pairing correlations appear at the domain wall.

Molecular formation influences phase separation stability.

Dynamics of spin-dipole mode are affected by bound states.

Abstract

We analyze how the presence of the bound state on top of strong intercomponent contact repulsion affects the dynamics of a two-component ultracold Fermi gas confined in a one-dimensional harmonic trap. By performing full many-body numerical calculations, we retrieve dynamics of an initially phase separated state that has been utilized to excite the spin-dipole mode in experimental settings. We observe an appearance of pairing correlations at the domain wall, heralding the onset of a molecular faction at the interlayer between the components. We find that such a mechanism can be responsible for the stabilization of the phase separation.