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

JIMÉNEZ, MARTÍN D.; CUESTAS, ELOISA; MAJTEY, ANA P.; CORMICK, CECILIA

SciPost Physics Core

SciPost Foundation

Lugar: Amsterdam; Año: 2023 vol. 6

We analyze a system of fermions in a one dimensional harmonic trap with attractivedelta-interactions between different fermions species, as an approximate description ofexperiments involving atomic dimers. We solve the problem of two fermion pairs numer-ically using the so-called “coboson formalism” as an alternative to techniques which arebased 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 ashard-core bosons. Our procedure is computationally inexpensive and illustrates how thecoboson toolbox is useful for ultracold atom systems even in absence of condensation.