Robust Field-Free Voltage-Gated Spin-Orbit Torque Switching in IrMn-Based Perpendicular Magnetic Tunnel Junctions

Spin-orbit torque (SOT) magnetic random-access memory (MRAM) is a promising candidate for next-generation memory technologies due to its non-volatility, high speed, and low power consumption. In this letter, we experimentally demonstrate SOT switching in 80 nm IrMn-based perpendicular magnetic tunnel junctions with a pulse width down to 0.8 ns. Field-free SOT switching is achieved with the assistance of the in-plane exchange bias (EB) generated at the antiferromagnetic/ferromagnetic interface. Remarkably, after 1× 1010 bipolar switchings, the stable field-free SOT switching can still be achieved, and the EB field remains at 3.25 mT, showing a robust EB and reliable SOT switching performance. The introduction of the voltage-controlled magnetic anisotropy effect results in a 35% reduction in power consumption. Furthermore, the voltage-gated SOT devices achieve a low write error rate below 5× 10-5 and a high endurance over 1× 1011 cycles. These findings highlight the potential of IrMn-based SOT-MRAM for advanced memory technology applications.