Double resonances in Borromean heteronuclear triatomic systems

TL;DR

This paper explores the unique behavior of Borromean three-body resonances in heteronuclear systems, revealing phenomena like double resonances and their temperature-dependent merging, relevant for ultracold atom experiments.

Contribution

It introduces a scaling function to analyze Borromean resonances and uncovers the occurrence of double resonances with implications for ultracold atom research.

Findings

Identification of double resonances with equal energies at different scattering lengths

Prediction of merging of recombination peaks with increasing temperature

Analysis of Efimov states in heteronuclear triatomic systems

Abstract

We investigate the occurrence of Borromean three-body continuum s-wave resonances, in an $\alpha\alpha\beta$ system for large negative two-body scattering lengths. The energy and width are determined by a scaling function with arguments given by energy ratios of the two-body virtual state subsystem energies with the shallowest three-body bound state. The Borromean continuum resonances emerging from Efimov states present a peculiar behavior for trapped ultracold atoms near a Feshbach resonance: two resonances with equal energies at different values of the scattering length. The corresponding three-body recombination peaks should merge as the temperature is raised, with one moving towards lower values of the scattering length as the other moves to larger values.