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The application of spin–orbit torque (SOT) devices to neuromorphic computing platforms is focused on the development of hardware circuit architectures. However, the inter-device variability, the integration modes of devices and peripheral circuits, and appropriate application scenarios are still unclear, limiting the development of SOT devices in neuromorphic computing. To solve this problem, this paper first proposes a circuit compensation scheme for the difference in resistance values of SOT devices, which solves this variability problem at the circuit level. Moreover, a synergistic scheme with the circuit is developed based on the correspondence between the multistate resistance characteristics of the SOT devices and a convolutional algorithm. To achieve this, a multichannel SOT convolutional kernel circuit architecture is built, which implements an image edge recognition application. Finally, based on a simulation model, an image edge recognition hardware circuit based on our CoPt-SOT devices is implemented, which is capable of performing image edge recognition with an accuracy of 96.33%. This scheme provides technical support and development prospects for SOT devices in neural network hardware applications. [ABSTRACT FROM AUTHOR]

Magnetic skyrmion, a nano-sized spin texture with topological property, have the potential to develop high-density, low-power, and multifunctional spintronic devices. To realize the reconfiguration of a single logic device and the implementation of the complete logic functions, a new reconfigurable and reusable skyrmion logic is proposed and verified by micromagnetic simulation. Logic functions including AND, OR, NOT, NAND and NOR are realized in ferromagnetic (FM) nanotrack by skyrmion-edge repulsions and the voltage control of magnetic anisotropy (VCMA) effect. The working state of the potential well can be controlled by the link of the input signals, thus changing the function type. In addition, through reusing skyrmion in circular track, the energy required for creation and deletion is reduced. This work can provide guidance for the design and optimization of reconfigurable and reusable logic devices with circular track based on skyrmion. [ABSTRACT FROM AUTHOR]

For real-world applications, it is desirable to realize field-free spin–orbit torque (SOT) switching in thin films with high perpendicular magnetic anisotropy (PMA). In this paper, we report that field-free SOT switching in a L10-FePt single layer with a large switching ratio of 26% is obtained by using a MgO ⟨100⟩⋀8°/⟨100⟩ miscut substrate. It is found that field-free switching depends on the direction of the imposed pulse current. Only when the electric current is along the y (010)-direction but not along the x (100)-direction does field-free switching happen, which can be attributed to the tilted PMA induced symmetry breaking in the x–z plane. Furthermore, under the field-free condition, our FePt single layer system exhibits stable multi-state magnetic switching behavior and nonlinear synaptic characteristics. This work paves the way to realize field-free SOT switching in the L10-FePt single layer, which will have significant impact on spin memory devices and synaptic electronics. [ABSTRACT FROM AUTHOR]