Kinetic formation of trimers and multimers in a spinless fermionic chain

We study a chain of spinless fermions with a multimer hopping term which kinematically favors the formation of multimers and competes with single-particle hopping. We argue that this model generically stabilizes two different multimer phases, as well as intermediate phases where the free-fermion and multimer fluids coexist and do not spatially separate. Using density-matrix renormalization group techniques, we establish the phase diagram of the model in the case of trimers. For one of the intermediate phases, hybridization between the fermions and trimers liquids does occur and the onset of their correlations is well captured by a generalized BCS-like ansatz. The case of tetramers is finally addressed.

Automated summary

In this study, we investigate a one-dimensional chain of spinless fermions with a multimer hopping term. We find that this chain can stabilize two distinct multimer phases and also exhibits intermediate phases where free fermions and multimer fluids coexist without spatial separation. We use density-matrix renormalization group techniques to establish the phase diagram of the model for the case of trimers and observe hybridization between fermions and trimer liquids in one of the intermediate phases.