Characterization of elastic scattering near a Feshbach resonance in rubidium 87

TL;DR

This paper measures the elastic scattering length of rubidium-87 atoms near a Feshbach resonance, confirming theoretical predictions and precisely determining the resonance's position and width through BEC expansion experiments.

Contribution

It provides the first precise experimental characterization of the scattering length near a Feshbach resonance in rubidium-87, aligning with theoretical models.

Findings

Resonance position at 1007.40 G

Resonance width of 0.20 G

Scattering length matches theoretical expectations

Abstract

The s-wave scattering length for elastic collisions between 87Rb atoms in the state |f,m_f>=|1,1> is measured in the vicinity of a Feshbach resonance near 1007 G. Experimentally, the scattering length is determined from the mean-field driven expansion of a Bose-Einstein condensate in a homogeneous magnetic field. The scattering length is measured as a function of the magnetic field and agrees with the theoretical expectation. The position and the width of the resonance are determined to be 1007.40 G and 0.20 G, respectively.