Ultracold molecules from ultracold atoms: a case study with the KRb molecule

TL;DR

This paper explores how ultracold collisions and resonances in atom-molecule systems like KRb can be controlled using quantum defect theory, focusing on long-range interactions and bound state properties.

Contribution

It demonstrates the application of multichannel quantum defect theory to ultracold KRb molecules, highlighting the control of resonances and bound states using long-range potential properties.

Findings

Resonances can be manipulated via quantum defect theory.

Bound state properties are characterized throughout the spectrum.

Long-range potential plays a key role in ultracold collision control.

Abstract

Ultracold collisions of cold atoms or molecules make the bound states of the collision complex formed from the two colliding species accessible for control and manipulation of the cold species or the complex. Such resonances are best treated by a resonant scattering theory, which in the ultracold domain can take advantage of the properties of the long-range potential and the methods of multichannel quantum defect theory. Coupled channels calculations on the threshold scattering states and bound states of the 40K87Rb molecule illustrate the ideas and methodology of quantum defect theory using the long-range potential and also demonstrate the spin properties of the bound states throughout the spectrum.