Self-binding of one-dimensional fermionic mixtures with zero-range interspecies attraction

TL;DR

This paper demonstrates that in one-dimensional fermionic mixtures with zero-range interspecies attraction, large mass ratios can lead to self-bound clusters forming a charge density wave, expanding understanding of binding phenomena in such systems.

Contribution

The study introduces a mean-field approach to show that large clusters in fermionic mixtures can self-bind into a charge density wave, highlighting the potential for self-bound states.

Findings

Large mass ratios enable cluster binding overcoming Fermi pressure

N+1 clusters can attract and form a self-bound charge density wave

No fundamental barriers to self-bound states in zero-range fermionic mixtures

Abstract

For sufficiently large mass ratios the attractive exchange force caused by a single light atom interacting with a few heavy identical fermions can overcome their Fermi degeneracy pressure and bind them into an $N+1$ cluster. Here, by using a mean-field approach valid for large $N$, we find that $N+1$ clusters can attract each other and form a self-bound charge density wave, the properties of which we fully characterize. Our work shows that there are no fundamental obstacles for having self-bound states in fermionic mixtures with zero-range interactions.