Spin Hall magnetoresistance sensor using Au$_x$Pt$_{1-x}$ as the spin-orbit torque biasing layer

TL;DR

This study develops a spin Hall magnetoresistance sensor using Au_xPt_{1-x} as the biasing layer, achieving lower power consumption and enhanced performance through optimized spin-orbit torque efficiency.

Contribution

The paper introduces a NiFe/Au_xPt_{1-x} based sensor with improved efficiency and performance, highlighting the benefits of using Au_xPt_{1-x} over pure Pt.

Findings

57% reduction in power consumption

80% enhancement of spin-orbit torque efficiency at x=0.19

Improved working field range, temperature range, and detectivity

Abstract

We report on investigation of spin Hall magnetoresistance sensor based on NiFe/AuxPt1-x bilayers. Compared to NiFe/Pt, the NiFe/AuxPt1-x sensor exhibits a much lower power consumption (reduced by about 57%), due to 80% enhancement of spin-orbit torque efficiency of AuxPt1-x at an optimum composition of x = 0.19 as compared to pure Pt. The enhanced spin-orbit torque efficiency allows to increase the thickness of NiFe from 1.8 nm to 2.5 nm without significantly increasing the power consumption. We show that, by increasing the NiFe thickness, we were able to improve the working field range (0.86 Oe), operation temperature range (150 degree C) and detectivity (0.71 nT/sqrt(Hz) at 1 Hz) of the sensor, which is important for practical applications.