Ultra-cold atoms quantum tunneling through single and double optical barriers

TL;DR

This paper demonstrates Bose-Einstein condensate tunneling through optical barriers, including single and double barriers, using tunable optical potentials and non-interacting 39K atoms, with applications in atom interferometry.

Contribution

It presents the first realization of atom tunneling through optical barriers with tunable widths and in-situ optical aberration characterization.

Findings

Successful demonstration of tunneling in the quantum scattering regime

Implementation of a tunable atomic Fabry-Pérot cavity

In-situ characterization of optical aberrations

Abstract

We realize textbook experiments on Bose-Einstein condensate tunnelling through thin repulsive potential barriers. In particular, we demonstrate atom tunnelling though a single optical barrier in the quantum scattering regime where the De Broglie wavelength of the atoms is larger than the barrier width. Such a beam splitter can be used for atom interferometry and we study the case of two barriers creating an atomic Fabry-P{\'e}rot cavity. Technically, the velocity of the atoms is reduced thanks to the use of a 39K Bose-Einstein condensate with no interactions. The potential barriers are created optically and their width is tunable thanks to the use of a digital micro-mirror device. In addition, our scattering experiments enable in-situ characterization of the optical aberrations of the barrier optical system.