Impurity immersed in a two-component few-fermion mixture in a one-dimensional harmonic trap

TL;DR

This paper studies a one-dimensional three-component fermion mixture with an impurity, revealing a critical interaction-induced structural transition with unique universal features and analyzing correlations and susceptibility.

Contribution

It uncovers a novel universal structural transition in a multi-component fermionic system driven by impurity interactions.

Findings

Identification of a critical impurity interaction strength

Observation of a structural transition with significant spatial change

Discovery of unique universality features in the transition

Abstract

We investigate a one-dimensional three-component few-fermion mixture confined in a parabolic external trap, where one component contains a single particle acting as an impurity. Focusing on the many-body ground state, we analyze how the interactions between the impurity and the other components influence the system's structure. For fixed interaction strengths within the mixture, we identify a critical interaction strength with the impurity for which the system undergoes a structural transition characterized by a substantial change in its spatial features. We explore this transition from the point of view of correlations and ground-state susceptibility. We remarkably find that this transition exhibits unique universality features not previously observed in other systems, highlighting novel many-body properties existing in multi-component fermionic mixtures.