Field‐Free Switching of Spin Crossbar Arrays by Asymmetric Spin Current Gradient

Spin orbit torque (SOT) devices with the advantages of high speed, low power consumption, and high stability have wide application prospects in the field of spintronics. The SOT‐based crossbar array device is an important extension of SOT devices, but it is not reported so far. Here, the all electrical magnetization switching of Hall crossings based on SOT crossbar array devices is realized. Through analyzing the current distribution and micromagnetic simulations, it is found that this field‐free SOT switching in the array devices comes from the asymmetric current density gradient distribution at the Hall‐crossings due to the shunt effect of grid circuits. All electrical tristate magnetization switching and the write protection of spin crossbar array devices are demonstrated. This work will further promote the application of the efficient memory or edge computing based on spin crossbar array devices. Field‐free magnetization switching is realized in 3 × 3 spin orbit torque crossbar array devices. Finite element and micromagnetic simulations reveal this field‐free switching comes from the asymmetric current density gradient distribution at the Hall‐crossings. The demonstration of tristate switching and the write protection will facilitate the study of spin crossbar array devices.