Symmetry-Breaking Zeeman-Coherence Parametric Wave Mixing Magnetometry

TL;DR

This paper introduces a novel nonlinear Zeeman-coherence parametric wave-mixing magnetometer that significantly enhances signal-to-noise ratio and reduces laser power requirements, enabling ultra-sensitive magnetic field detection at room temperature.

Contribution

The authors demonstrate a new wave-mixing magnetometry technique that greatly improves sensitivity and efficiency over traditional methods using room temperature rubidium vapor.

Findings

Over three orders of magnitude SNR enhancement.

Nearly two orders of magnitude reduction in laser power.

Maintains high sensitivity comparable to existing methods.

Abstract

The nonlinear magneto-optical effect has significantly impacted modern society with prolific applications ranging from precision mapping of the Earth's magnetic field to bio-magnetic sensing. Pioneering works on collisional spin-exchange effects have led to ultra-high magnetic field detection sensitivities at the level of $fT/\sqrt{Hz}$ using a single linearly-polarized probe light field. Here we demonstrate a nonlinear Zeeman-coherence parametric wave-mixing optical-atomic magnetometer using room temperature rubidium vapor that results in more than a three-order-of-magnitude optical signal-to-noise ratio (SNR) enhancement for extremely weak magnetic field sensing. This unprecedented enhancement was achieved with nearly a two-order-of-magnitude reduction in laser power while preserving the sensitivity of the widely-used single-probe beam optical-atomic magnetometry method. This new method opens a myriad of applications ranging from bio-magnetic imaging to precision measurement of the magnetic properties of subatomic particles.