Magnetic Induction Imaging with a cold-atom radio-frequency magnetometer

TL;DR

This paper demonstrates a cold-atom-based radio-frequency magnetometer capable of imaging small metallic objects with high sensitivity in unshielded environments, suitable for surveillance applications.

Contribution

It introduces a novel cold-atom RF magnetometer that performs 1-D and 2-D imaging without active stabilization, operating effectively in unshielded settings.

Findings

Sensitivity up to 200 pT/√Hz in 5-35 kHz range

Resolves metallic features as small as 0.4 mm wide

Operates without active field stabilization

Abstract

The sensitive detection of either static or radio-frequency \textsc{(rf)} magnetic fields is essential to many fundamental studies and applications. Here, we demonstrate the operation of a cold-atom-based, \textsc{rf} magnetometer in performing {1-D and 2-D imaging} of small metallic objects. It is based on a cold $^{85}$Rb atomic sample, and operates in an unshielded environment with no active field stabilization. It shows a sensitivity up to $200\, \rm{pT}/\sqrt{\rm Hz}$ in the $5-35\, \rm{kHz}$ range bandwidth and can resolve a cut $0.4\, \rm{mm}$ wide in a $0.8\, \rm{mm}$ thick metallic foil. The characteristics of our system make it a good candidate for applications in civil and industrial surveillance.