Multichannel quantum-defect theory for magnetic Feshbach resonances in heteronuclear group I systems

TL;DR

This paper develops a multichannel quantum-defect theory to comprehensively describe magnetic Feshbach resonances in heteronuclear group I atom interactions, covering all partial waves and enabling efficient characterization of resonances.

Contribution

It introduces a unified quantum-defect framework for all partial waves in heteronuclear group I systems, simplifying resonance characterization with few parameters.

Findings

All resonances in $^6$Li$^{40}$K are described across multiple channels and partial waves.

The theory accurately characterizes resonances using Gao's parametrization.

The approach applies over a broad magnetic field range from 0 to 1000 Gauss.

Abstract

We present a multichannel quantum-defect theory for magnetic Feshbach resonances in the interaction of two heteronuclear group I atoms. The theory provides a unified and a uniform description of resonances in all partial waves, and enables the characterization of large number of resonances in terms of very few parameters. For the sample system of $^6$Li$^{40}$K, we present descriptions of all resonances in $aa$, $ab$, and $ba$ channels, in partial waves $s$ ($l=0$) through $h$ ($l=5$), and in a magnetic field of 0 through 1000 Gauss. All resonances, including those in nonzero partial waves, are fully characterized using the newly developed parametrization of Gao [Phy. Rev. A \textbf{84}, 022706 (2011)].