Sensitive BEC magnetometry with optimized probing

TL;DR

This paper presents an advanced BEC-based magnetometer with enhanced sensitivity and spatial resolution, achieved through optimized probing techniques and phase contrast imaging, surpassing many existing low-frequency magnetometers.

Contribution

It introduces a novel two-polarization phase contrast imaging method and optimized probe parameters to significantly improve BEC magnetometry sensitivity.

Findings

Achieved 7.7 pT/√Hz sensitivity over 28 μm² area

Optical shot noise suppressed via probe parameter optimization

Sensitivity per unit area exceeds other low-frequency magnetometers

Abstract

An improved spatial magnetometer using a spinor Bose-Einstein condensate of $^{87}$Rb atoms is realized utilizing newly developed two-polarization phase contrast imaging. The optical shot noise is suppressed by carefully choosing the probe parameters. We attain a dc-magnetic field sensitivity of 7.7 ${\rm pT/\sqrt{Hz}}$ over a measurement area of 28 ${\rm \mu m^{2}}$. The attained sensitivity per unit area is superior to that for other modern low-frequency magnetometers with micrometer-order spatial resolution. This result is a promising step for realizing quantum-enhanced magnetometry surpassing classical methods.