Spin Orbit Torque Locally Controlling Exchange Bias to Realize High Detection Sensitivity of Two-dimensional Magnetic Field

Abstract

Spin orbit torque (SOT) of spin current has provided an efficient manipulation of ferromagnet order, antiferromagnet order, and exchange bias field for various spintronic applications. Here, in contrast to the external magnetic field which is very hard to apply locally, we propose to utilize the local control characteristic of SOT on the macro-nano-meter scale to set four different directions of exchange bias field at the IrMn/CoFe interface on one chip simultaneously. Moreover, with this fully electrical control technology to replace the existing various complex processes based on magnetic field annealing, we fabricate monolithic dual-axis full Wheatstone-bridge magnetoresistance sensors to detect two-dimensional magnetic field vector, which exhibit very high detection sensitivity of 9.45 nT·Hz−1/2 and 12.3 nT·Hz−1/2 at 10 Hz for X-axis and Y-axis sensing, respectively. This work provides a paradigm to simultaneously implement function configurations of spintronic devices by using the local control characteristic of SOT.