Efimov-van-der-Waals universality for ultracold atoms with positive scattering lengths

TL;DR

This paper investigates the universal behavior of three-body parameters in ultracold atoms with positive scattering lengths, considering finite-range effects and the influence of d-wave interactions, providing insights relevant for experimental validation.

Contribution

It introduces a comprehensive analysis of three-body universality in ultracold atoms, accounting for finite-range effects and the impact of d-wave interactions, which was not thoroughly explored before.

Findings

Three-body parameters are constrained by a variational principle.

Finite-range effects influence the universality of Efimov states.

D-wave interactions can prevent Efimov states from merging into the atom-dimer continuum.

Abstract

We study the universality of the three-body parameters for systems relevant for ultracold quantum gases with positive $s$-wave two-body scattering lengths. Our results account for finite-range effects and their universality is tested by changing the number of deeply bound diatomic states supported by our interaction model. We find that the physics controlling the values of the three-body parameters associated with the ground and excited Efimov states is constrained by a variational principle and can be strongly affected by $d$-wave interactions that prevent both trimer states from merging into the atom-dimer continuum. Our results enable comparisons to current experimental data and they suggest tests of universality for atomic systems with{positive scattering lengths.