Axicon Lens for Coherent Matter Waves

TL;DR

This paper demonstrates a novel conical matter wave lens using a focused laser beam to create a ring-shaped Bose-Einstein condensate, enabling cylindrical atom optics with minimal interaction effects.

Contribution

The authors realized a conical matter wave lens that produces a narrow, ring-shaped BEC, advancing atom optics by reducing mean-field interaction perturbations.

Findings

Successfully launched a BEC into a ring-shaped wavepacket

Maintained narrow spatial and velocity widths despite interactions

Numerical simulations confirmed experimental results

Abstract

We have realized a conical matter wave lens. The repulsive potential of a focused laser beam was used to launch a Bose-Einstein condensate into a radially expanding wavepacket whose perfect ring shape was ensured by energy conservation. In spite of significant interactions between atoms, the spatial and velocity widths of the ring along its radial dimension remained extremely narrow, as also confirmed by numerical simulations. Our results open the possibility for cylindrical atom optics without the perturbing effect of mean-field interactions.