Quantum rainbow scattering at tunable velocities

TL;DR

This study measures elastic scattering cross sections of lithium with rare gases and SF6 at tunable velocities, revealing quantum effects like rainbows and resonances through combined experimental and theoretical analysis.

Contribution

It introduces a novel experimental setup combining a velocity-tunable beam with an ultracold lithium cloud to explore quantum collision dynamics.

Findings

Observation of quantum rainbows in scattering patterns

Detection of orbiting resonances at low velocities

Agreement between experimental data and quantum scattering theory

Abstract

Elastic scattering cross sections are measured for lithium atoms colliding with rare gas atoms and SF6 molecules at tunable relative velocities down to ~50 m/s. Our scattering apparatus combines a velocity-tunable molecular beam with a magneto-optic trap that provides an ultracold cloud of lithium atoms as a scattering target. Comparison with theory reveals the quantum nature of the collision dynamics in the studied regime, including both rainbows as well as orbiting resonances.