Spin–orbit-torque-enabled giant magnetoresistance sensor

Spin–orbit torque (SOT) offers a route to compact angular and linear magnetic sensors, but their output is typically lower than conventional magnetoresistance sensors. We extend the SOT-based design to Wheatstone-bridge giant magnetoresistance (GMR) sensors, achieving offset- and hysteresis-free operation. Despite a large GMR ratio, detectivity does not scale directly, highlighting the need to balance sensitivity and working range. By tuning the longitudinal magnetic field to emulate various interlayer-coupling conditions, we map this trade-off, reaching a maximum sensitivity of 5 mV/V/mT, a working range of up to 2.2 mT, and a detectivity of ∼300nT/Hz under optimized conditions. These results establish SOT-enabled linearization in a GMR spin-valve bridge and identify sensing-layer softening, reduced current shunting, and enhanced SOT efficiency as key routes to higher detectivity with lower power consumption.