Composite-boson formalism applied to strongly bound fermion pairs in a one-dimensional trap

TL;DR

This paper uses the coboson formalism to analyze strongly bound fermion pairs in a one-dimensional trap, providing a computationally efficient approach to study their behavior approaching the hard-core boson limit.

Contribution

It introduces the coboson formalism as an alternative to traditional methods for analyzing strongly bound fermion pairs in ultracold atom systems.

Findings

Successfully applied coboson formalism to two fermion pairs

Explored the strongly bound regime approaching infinite attraction

Demonstrated the method's computational efficiency

Abstract

We analyze a system of fermions in a one-dimensional harmonic trap with attractive delta-interactions between different fermions species, as an approximate description of experiments involving atomic dimers. We solve the problem of two fermion pairs numerically using the so-called ''coboson formalism'' as an alternative to techniques which are based on the single-particle basis. This allows us to explore the strongly bound regime, approaching the limit of infinite attraction in which the composite particles behave as hard-core bosons. Our procedure is computationally inexpensive and illustrates how the coboson toolbox is useful for ultracold atom systems even in absence of condensation.