Extraordinary magnetometry -- a review on extraordinary magnetoresistance

TL;DR

This review comprehensively covers the state-of-the-art in extraordinary magnetoresistance (EMR) sensors, highlighting device geometries, material properties, and applications, and discusses future directions for enhancing magnetic field sensing technology.

Contribution

It provides an extensive comparison of EMR devices, analyzes the influence of geometry and materials, and offers insights into optimizing EMR for sensitive magnetic field detection.

Findings

EMR can exceed 107% resistance change at room temperature with 5 T magnetic field.

Device geometry and material properties significantly influence EMR performance.

Current EMR sensors show potential but are yet to fully realize their sensitivity capabilities.

Abstract

Extraordinary magnetoresistance (EMR) is a geometric magnetoresistance effect occurring in hybrid devices consisting of a high-mobility material joined by a metal. The change in resistance can exceed 107% at room temperature when a magnetic field of 5 T is applied. Magnetic field sensors based on EMR hold the potential formeasuring weak magnetic fields with an unprecedented sensitivity, yet, to date this potential is largely unmet. In this work, we provide an extensive review of the current state-of-the-art in EMR sensors with a focus on the hybrid device geometries, the constituent material properties and applications of EMR. We present a direct comparison of the best devices in literature across magnetoresistance, sensitivity and noise equivalent field for different materials and geometric designs. The compilation of studies collected in this review illustrates the extremely rich possibilities for tuning the magnetoresistive behavior varying the device geometry and material properties. In addition, we aim to improve the understanding of the EMR effect and its interplay with geometry and material properties. Finally, we discuss recent trends in the field and future perspectives for EMR.