Gradiometry-free noise suppression in RF atomic magnetometers

TL;DR

This paper introduces a novel RF atomic magnetometer that detects the polarization state of magnetic fields, enabling noise suppression without traditional gradiometry, and exhibits orientation sensitivity based on the phase of the signal.

Contribution

The work demonstrates polarization-based noise suppression in RF atomic magnetometers, offering a new approach to signal detection that is independent of source distance and traditional gradiometry methods.

Findings

>36 dB difference in amplitude sensitivity for opposite circular polarizations

Sensor's phase depends on the angle between detection axis and transmitter

Potential for noise suppression regardless of source distance

Abstract

We demonstrate the sensitivity of a sensor based on an optically-pumped radio-frequency (RF) atomic magnetometer to the polarization state of the detected RF magnetic field, and measure $>$36 dB difference in amplitude sensitivity for opposite circular field polarizations. This sensitivity could be used to create novel sensors that would allow signal detection while suppressing the ambient noise, regardless of the distance between the sources of signal and noise, in contrast to traditional gradiometry configurations. Additionally, such sensor will be orientation-sensitive, as the phase of the detected signal is shown to depend on the angle between the sensor's detection axis and the direction to the transmitter.