An Atom Laser is not monochromatic

TL;DR

This paper demonstrates through numerical and analytical methods that atom lasers are inherently non-monochromatic due to interatomic interactions, using a Mach-Zehnder interferometer setup with Bose-Einstein condensates.

Contribution

It introduces a novel approach to constructing a Mach-Zehnder interferometer for BECs and reveals the fundamental non-monochromatic nature of atom lasers.

Findings

Interatomic interactions cause atom lasers to be non-monochromatic.

Interference fringes are affected by the entanglement in the system.

The setup mimics optical MZI with BECs in the time domain.

Abstract

We study both numerically and analytically the possibility of using an adiabatic passage control method to construct a Mach-Zehnder interferometer (MZI) for Bose-Einstein condensates (BECs) in the time domain, in exact one-to-one correspondence with the traditional optical MZI that involves two beam splitters and two mirrors. The interference fringes one obtains from such a minimum-disturbance set up clearly demonstrates that, fundamentally, an atom laser is not monochromatic due to interatomic interactions. We also consider how the amount of entanglement in the system correlates to the interference fringes.