Magnetic control of the interaction in ultracold K-Rb mixtures

TL;DR

This paper predicts multiple magnetic Feshbach resonances in ultracold K-Rb mixtures, enabling control over interactions for advanced quantum phenomena and molecule formation.

Contribution

It combines new inelastic cross section measurements with recent data to identify Feshbach resonances in specific K-Rb isotopic pairs at high magnetic fields.

Findings

Identification of several Feshbach resonances up to 1000 G

Potential to tune interactions from weak to strong coupling

Implications for Cooper pairing and ultracold molecule production

Abstract

We predict the presence of several magnetic Feshbach resonances in selected Zeeman sublevels of the isotopic pairs K(40)-Rb(87) and K(41)-Rb(87) at magnetic fields up to 1000 G. Positions and widths are determined combining a new measurement of the K(40)-Rb(87) inelastic cross section with recent experimental results on both isotopes. The possibility of driving a K-Rb mixtures from the weak to the strong interacting regime tuning the applied field should allow to achieve the optimal conditions for boson-induced Cooper pairing in a multi component K(40)-Rb(87) atomic gas and for the production of ultracold polar molecules.