Loading and compression of a single two-dimensional Bose gas in an optical accordion

TL;DR

This paper demonstrates the creation of a tunable two-dimensional Bose gas using an optical accordion lattice with adjustable spacing, enabling control over confinement and interaction strength in ultracold quantum gases.

Contribution

It introduces a novel optical accordion setup that allows dynamic tuning of lattice spacing and confinement for 2D Bose gases, advancing control in ultracold atom experiments.

Findings

Successfully loaded ultracold atoms into a single lattice node.

Achieved nearly adiabatic reduction of lattice spacing to increase confinement.

Created uniform 2D Bose gases with tunable interaction strength.

Abstract

The experimental realization of 2D Bose gases with a tunable interaction strength is an important challenge for the study of ultracold quantum matter. Here we report on the realization of an optical accordion creating a lattice potential with a spacing that can be dynamically tuned between 11$\,\mu$m and 2$\,\mu$m. We show that we can load ultracold $^{87}$Rb atoms into a single node of this optical lattice in the large spacing configuration and then decrease nearly adiabatically the spacing to reach a strong harmonic confinement with frequencies larger than $\omega_z/2\pi=10\,$kHz. Atoms are trapped in an additional flat-bottom in-plane potential that is shaped with a high resolution. By combining these tools we create custom-shaped uniform 2D Bose gases with tunable confinement along the transverse direction and hence with a tunable interaction strength.