Reconfigurable Logic Operations via Gate Controlled Skyrmion Motion in a Nanomagnetic Device

Owing to the topological protection and the ease of efficient manipulation, skyrmions have emerged as potential candidates for carrying information in future memory and logic devices. Here, we have proposed a reconfigurable skyrmion based two-input logic device architecture. Using micromagnetic simulations, we have demonstrated that the device is capable of performing both OR and AND logic gate functionalities in a reconfigurable manner. Different logic functionality of the device is selected by using a current through a nonmagnetic metallic gate, and the resultant Oersted field controls the trajectory of the skyrmion, which in turn determines the logic states. The logic functions are implemented on a ferromagnet/heavy metal bilayer device structure by virtue of several physical effects, such as the spin–orbit torque, skyrmion–edge repulsion, skyrmion–skyrmion topological repulsion, and skyrmion Hall effect. The skyrmion trajectory has been characterized by estimating the skyrmion Hall angle. A wide range of operations by varying the current density, skyrmion velocity, Dzyaloshinskii–Moriya interaction, magnetic anisotropy, and geometrical parameters have been presented in detail. We believe that our spin orbit torque driven logic design will have potential implications for a high-speed and low-power skyrmion based computing architecture.