Binding of $N+1$-clusters in mass-imbalanced fermionic mixtures in low dimensions
Jules Givois (LPTMS)
In the last 10 years, the few-body bound states made of $1$ light fermion interacting attractively with $N$ heavy fermions were analyzed in all spatial dimensions. To address the large $N$ limit and to investigate the formation of $N+1$ clusters in fermionic mixtures with weak attraction, we developed a mean-field approach based on the Thomas-Fermi approximation for the heavy atoms kinetic energy in both one and two dimensions. We find that in the two cases the $N$ heavy fermions can be bound by a single light fermion as long as the mass-ratio is large enough. We show that the bound character of the system can be described by a single parameter that depends on the dimensions and which combines the mass-ratio and $N$. In two dimensions, scale invariance plays a determinant role and we present a way to overcome it using beyond mean-field corrections.