Ultracold atoms in an optical lattice with dynamically variable periodicity

TL;DR

This paper demonstrates a dynamic optical lattice for ultracold atoms that can vary its periodicity during experiments, enabling quantum simulations with adjustable lattice spacing and improved imaging capabilities.

Contribution

Introduces a method to dynamically change the lattice spacing in an optical lattice with ultracold atoms, facilitating advanced quantum simulation and imaging techniques.

Findings

Atoms remain bound during rapid lattice expansion.

Minimum ramp time matches numerical predictions.

Technique enables sub-resolution imaging of atoms.

Abstract

The use of a dynamic "accordion" lattice with ultracold atoms is demonstrated. Ultracold atoms of $^{87}$Rb are trapped in a two-dimensional optical lattice, and the spacing of the lattice is then increased in both directions from 2.2 to 5.5 microns. Atoms remain bound for expansion times as short as a few milliseconds, and the experimentally measured minimum ramp time is found to agree well with numerical calculations. This technique allows an experiment such as quantum simulations to be performed with a lattice spacing smaller than the resolution limit of the imaging system, while allowing imaging of the atoms at individual lattice sites by subsequent expansion of the optical lattice.