Matter wave scattering on an amplitude-modulated optical lattice

TL;DR

This paper experimentally investigates how guided matter waves scatter on an amplitude-modulated optical lattice, revealing frequency-dependent dips in output density and proposing a tunable velocity filter based on bichromatic modulation.

Contribution

It introduces a semiclassical Floquet-Bloch model to explain matter wave scattering phenomena and demonstrates a novel, species-independent velocity filtering technique.

Findings

Observed frequency-dependent dips in matter wave density distribution.

Validated the semiclassical model with numerical simulations.

Demonstrated a tunable sub-recoil velocity filter using bichromatic modulation.

Abstract

We experimentally study the scattering of guided matter waves on an amplitude-modulated optical lattice. We observe different types of frequency-dependent dips in the asymptotic output density distribution. Their positions are compared quantitatively with numerical simulations. A semiclassical model that combines \emph{local} Floquet-Bloch bands analysis and Landau-Zener transitions provides a simple picture of the observed phenomena in terms of elementary \emph{Floquet photon} absorption-emission processes and envelope-induced reflections. Finally, we propose and demonstrate the use of this technique with a bichromatic modulation to design a tunable sub-recoil velocity filter. Such a filter can be transposed to all species since it does not rely on a specific internal level configuration of the atoms.