Two-Fluid Coexistence in a Spinless Fermions Chain with Pair Hopping

We show that a simple one-dimensional model of spinless fermions with pair hopping displays a phase in which a Luttinger liquid of paired fermions coexists with a Luttinger liquid of unpaired fermions. Our results are based on extensive numerical density-matrix renormalization-group calculations and are supported by a two-fluid model that captures the essence of the coexistence region.

Automated summary

In this study, a simple one-dimensional model of spinless fermions with pair hopping is investigated, revealing a phase where a Luttinger liquid of paired fermions coexists with a Luttinger liquid of unpaired fermions. Extensive numerical density-matrix renormalization-group calculations are performed, supported by a two-fluid model capturing the essence of this coexistence region.