Optically guided beam splitter for propagating matter waves

TL;DR

This paper investigates an optically guided atom laser beam splitter, demonstrating controllable splitting and guiding behaviors in a horizontal optical setup, with potential applications in quantum control of matter waves.

Contribution

It introduces a novel optical beam splitter for matter waves capable of switching and splitting, with robustness against parameter variations and a proposed controlled two-channel scheme.

Findings

The system can act as a perfect guide switch or a beam splitter.

Splitting arises from chaotic scattering dynamics.

The proposed scheme offers a robust, controlled two-channel beam splitter.

Abstract

We study experimentally and theoretically a beam splitter setup for guided atomic matter waves. The matter wave is a guided atom laser that can be tuned from quasi-monomode to a regime where many transverse modes are populated, and propagates in a horizontal dipole beam until it crosses another horizontal beam at 45$^{\rm o}$. We show that depending on the parameters of this $X$ configuration, the atoms can all end up in one of the two beams (the system behaves as a perfect guide switch), or be split between the four available channels (the system behaves as a beam splitter). The splitting regime results from a chaotic scattering dynamics. The existence of these different regimes turns out to be robust against small variations of the parameters of the system. From numerical studies, we also propose a scheme that provides a robust and controlled beam splitter in two channels only.