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

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+1N+1 cluster. Here, by using a mean-field approach valid for large NN, we find that N+1N+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.