Magnetic noise spectrum measurement by an atom laser in gravity

TL;DR

This paper investigates how Bose-Einstein condensates can be used as sensitive magnetic noise detectors by analyzing the spectral resolution function of an atom laser under gravity, considering various condensate geometries.

Contribution

It introduces a detailed quantum mechanical model of the spectral resolution function for atom laser-based magnetic noise measurement, including gravitational effects and different condensate configurations.

Findings

Derived the position-dependent spectral resolution function.

Compared intuitive and exact quantum approaches.

Analyzed effects of condensate size and shape.

Abstract

Bose-Einstein condensates of ultracold atoms can be used to sense fluctuations of the magnetic field by means of transitions into untrapped hyperfine states. It has been shown recently that counting the outcoupled atoms can yield the power spectrum of the magnetic noise. We calculate the spectral resolution function which characterizes the condensate as a noise measurement device in this scheme. We use the description of the radio-frequency outcoupling scheme of an atom laser which takes into account the gravitational acceleration. Employing both an intuitive and the exact three-dimensional and fully quantum mechanical approach we derive the position-dependent spectral resolution function for condensates of different size and shape.