High-sensitive and fast-response three-dimensional magnetic sensor based on spin–orbit torque

Abstract

Spin–orbit torque-based three-dimensional (3D) magnetic sensors have emerged as a prominent research focus due to their potential for high-precision magnetic field detection and high integration density. Despite these advantages, significant challenges remain, including suboptimal performance response time and limitations in sensitivity. In this work, we address these challenges by demonstrating a 3D magnetic field sensor based on a hysteresis-free W/CoFeB/MgO heterostructure. The magnetization of the CoFeB layer rapidly reaches equilibrium upon current application, enabling simultaneous excitation and signal reading through a single 50 μs current pulse. This sensor allows for fast measurements of vectoral magnetic fields while maintaining high spatial resolution. Under an excitation current density of only 0.95 MA/cm2, the sensor demonstrates ultrahigh sensitivity, with values of 1463, 1650, and 4881 V/A/T for the x-, y-, and z-axis magnetic field components respectively. Additionally, the sensor achieves a magnetic noise level as low as 14.7 nT/√Hz at 1 Hz, highlighting its exceptional accuracy.