# Assembly of 2N entangled fermions into multipartite composite bosons

## TL;DR

This paper investigates how groups of 2N fermions can form composite bosons, proposing an entanglement-based method to evaluate their bosonic behavior and studying the ground state transitions in a Hubbard model.

## Contribution

It introduces a novel entanglement-based approach to determine the bosonic nature of fermionic arrangements and applies it to a Hubbard model analysis.

## Key findings

- Entanglement measures can assess bosonic quality of fermionic composites.
- Ground state properties change with interaction strength in the Hubbard model.
- Multiple fermionic arrangements influence the emergent bosonic behavior.

## Abstract

An even number of fermions can behave in a bosonic way. The simplest scenario involves two fermions which can form a single boson. But four fermions can either behave as two bipartite bosons or further assemble into a single four-partite bosonic molecule. In general, for 2N fermions there are many possible arrangements into composite bosons. The question is: what determines which fermionic arrangement is going to be realized in a given situation and can such arrangement be considered truly bosonic? This work aims to find the answer to the above question. We propose an entanglement-based method to assess bosonic quality of fermionic arrangements and apply it to study how the ground state of the extended one-dimensional Hubbard model changes as the strength of intra-particle interactions increases.