Fourier synthesis of optical potentials for atomic quantum gases

TL;DR

This paper presents a method to synthesize complex optical potentials for atomic gases using Fourier techniques, enabling the creation of asymmetric and unconventional lattice structures for quantum experiments.

Contribution

It introduces a novel Fourier synthesis scheme for optical potentials, demonstrated with Bose-Einstein condensates and combining different lattice periodicities.

Findings

Successfully created symmetric and asymmetric optical potentials.

Demonstrated superposition of $\lambda/2$ and $\lambda/4$ periodicity lattices.

Potential applications include novel quantum phases and atomic ratchets.

Abstract

We demonstrate a scheme for the Fourier synthesis of periodic optical potentials with asymmetric unit cells for atoms. In a proof of principle experiment, an atomic Bose-Einstein condensate is exposed to either symmetric or sawtooth-like asymmetric potentials by superimposing a conventional standing wave potential of $\lambda/2$ spatial periodicity with a fourth-order lattice potential of $\lambda/4$ periodicity. The high periodicity lattice is realized using dispersive properties of multiphoton Raman transitions. Future applications of the demonstrated scheme could range from the search for novel quantum phases in unconventionally shaped lattice potentials up to dissipationless atomic quantum ratchets.