Advances in magnetometry

TLDR

Recent progress in magnetometry builds on existing technology and is framed by a discussion of current limitations. The article reviews recent advances in magnetometry. The advances stem from deeper insight into spin‑dominated transport in multilayers and magnetic tunnel junctions. Advances include higher magnetoresistance, improved signal processing, novel magnetoelectric, extraordinary magnetoresistance, and MEMS‑based sensors, yielding orders‑of‑magnitude sensitivity gains and reduced cost and power.

Abstract

This article describes many of the advances in magnetometry. Because much of the recent progress in magnetometry is built on current technology, and to put these advances in the proper perspective, a general discussion of magnetometry will also be presented. The progress includes a remarkable increase in the magnetoresistance of some devices, improved signal processing, and some new types of magnetometer. The large increase in magnetoresistance is a result of an increased understanding of quantum mechanical spin dominated transport in restricted geometries such as multilayers and magnetic tunnel junctions. The new types of magnetometer include magnetoelectric sensors, extraordinary magnetoresistance sensors, and sensors that incorporate MEMS technology. These advances in magnetometer technology offer orders of magnitude increases in sensitivity and/or large decreases in cost and power consumption. Major technological limitations of current magnetic sensors are also discussed.