Feshbach spectroscopy and analysis of the interaction potentials of ultracold sodium

TL;DR

This study investigates magnetic Feshbach resonances in ultracold sodium, identifying multiple resonance types, refining interaction potentials, and providing a detailed molecular state analysis to enhance understanding of sodium interactions.

Contribution

The paper presents new experimental data on sodium Feshbach resonances and improves interaction potential models using coupled-channels calculations and asymptotic-bound-state analysis.

Findings

Identification of 3 s-, 8 d-, and 3 g-wave Feshbach resonances

Refined sodium ground-state interaction potentials

Accurate scattering length values derived

Abstract

We have studied magnetic Feshbach resonances in an ultracold sample of Na prepared in the absolute hyperfine ground state. We report on the observation of three s-, eight d-, and three g-wave Feshbach resonances, including a more precise determination of two known s-wave resonances, and one s-wave resonance at a magnetic field exceeding 200mT. Using a coupled-channels calculation we have improved the sodium ground-state potentials by taking into account these new experimental data, and derived values for the scattering lengths. In addition, a description of the molecular states leading to the Feshbach resonances in terms of the asymptotic-bound-state model is presented.