Efimov physics in heteronuclear four-body systems

TL;DR

This paper investigates Efimov physics in heteronuclear four-body systems, revealing how atom exchange influences low-energy scattering and clarifying the absence of a true four-body Efimov effect, with implications for ultracold experiments.

Contribution

It demonstrates the role of light atom exchange in three- and four-body Efimov features and resolves the long-standing debate on the existence of a four-body Efimov effect.

Findings

Exchange of light atoms leads to observable Efimov features in inelastic rates.

No infinite four-body bound states exist without two- or three-body bound states.

Effective interactions can be used for control in ultracold atomic experiments.

Abstract

We study three- and four-body Efimov physics in a heteronuclear atomic system with three identical heavy bosonic atoms and one light atom. We show that exchange of the light atom between the heavy atoms leads to both three- and four-body features in the low-energy inelastic rate constants that trace to the Efimov effect. Further, the effective interaction generated by this exchange can provide an additional mechanism for control in ultracold experiments. Finally, we find that there is no true four-body Efimov effect - that is, no infinite number of four-body states in the absence of two- and three-body bound states - resolving a decades-long controversy.