A scalable high-performance magnetic shield for Very Long Baseline Atom Interferometry

TL;DR

This paper presents a modular, high-performance magnetic shield designed for Very Long Baseline Atom Interferometry, achieving ultra-low residual magnetic fields and inhomogeneities over 8 meters, enabling precise tests of fundamental physics.

Contribution

The paper introduces a scalable, high-performance magnetic shielding design that maintains low residual fields over extended baselines for VLBAI applications.

Findings

Residual magnetic fields below 4 nT achieved

Longitudinal inhomogeneities below 2.5 nT/m over 8 m

Modular design allows extension without performance loss

Abstract

We report on the design, construction, and characterization of a 10 m-long high-performance magnetic shield for Very Long Baseline Atom Interferometry (VLBAI). We achieve residual fields below 4 nT and longitudinal inhomogeneities below 2.5 nT/m over 8 m along the longitudinal direction. Our modular design can be extended to longer baselines without compromising the shielding performance. Such a setup constrains biases associated with magnetic field gradients to the sub-pm/$\textrm{s}^2$ level in atomic matterwave accelerometry with rubidium atoms and paves the way towards tests of the universality of free fall with atomic test masses beyond the $10^{-13}$ level.