Skyrmion based logic devices are found to be promising for next-generation energy-efficient, high speed information processing technologies owing to the compact size and topologically protected spin texture of the skyrmions 1,2. Skyrmions are nano-scale swirling spin textures with topological protection that exhibit particle-like behaviour. In this work, we exploit skyrmion for various logic operations using a Gate to locally alter the magnetic properties that control the skyrmion motion in the logic device using micromagnetic simulation. For example, we have shown the OR and AND logic operations in a single device by flowing current through a metallic gate and the resultant Oersted field (HOe) controls the skyrmion trajectory (Fig. 1(a)). The HOe generated near the Gate is one of the efficient ways to realize the logic operations 3. By simply switching OFF and ON the current at the metallic gate, we can toggle between OR & AND logic operations (Fig. 1(b & c)), respectively. The binary information is denoted by the presence and absence of the skyrmion as “1” and “0”, respectively. Fig. 1(d) shows the realization of the AND logic for a specific combination of skyrmion driving current density (j) and HOe. The logic functions are implemented in the device structure by virtue of several physical effects on skyrmion motion such as spin-orbit torque, skyrmion-edge repulsion, skyrmion-skyrmion topological repulsion and skyrmion Hall effect. To understand the motion of the skyrmions and stability, we estimated the Skyrmion Hall angle. The performance of the logic device is studied by varying the material and geometrical parameters. In this presentation, we would like to explain various logic operations including a majority logic device based on skyrmions with different Gate operation schemes and novel logic device architectures for computation. The results are interesting for next generation energy-efficient and high-density computing technologies.
References
1 A. Fert, V. Cros, and J. Sampaio, Nature Nanotechnology 8, 152 (2013). 2 Luo S., Y. Long, APL Materials 9, 050901 (2021). 3 B. Paikaray, M. Kuchibhotla, A. Haldar, and C. Murapaka, ACS Applied Electronic Materials 4, 2290-2297, (2022).