Kinetic formation of trimers in a spinless fermionic chain

TL;DR

This paper demonstrates the formation of stable trimer phases in a spinless fermionic chain with correlated hopping, revealing complex coexistence and hybridization phenomena, and extends findings to larger multimers.

Contribution

It introduces the stabilization of trimer phases in a fermionic chain with correlated hopping and explores their coexistence, hybridization, and extension to larger multimers.

Findings

Two stable trimer phases identified

Coexistence of fluids without spatial separation

Hybridization captured by a generalized BCS ansatz

Abstract

We show the stabilization of two trimer phases in a chain of spinless fermions with a correlated hopping term. A trimer fluid forms due to a gain in trimer kinetic energy and competes with a fluid of unbound fermions. Furthermore, we observe two intermediate phases where these two fluids coexist and do not spatially separate. Depending on the way trimers are created out of the Fermi sea, hybridization can occur, in which case the onset of correlations between the two fluids is well captured by a generalized BCS ansatz. These results are finally extended to the formation of larger multimers, which highlights the peculiarities of pair and trimer formation.