Skyrmion based universal logic gates and computation operation

Abstract

Swirling spin configurations with a non-trivial topological state are popularly known as magnetic
skyrmions. They are often observed in magnetic thin films with perpendicular magnetic anisotropy
and Dzyaloshinskii-Moriya interaction. Due to their small size and non-colinear spin texture, they
are being considered as a potential candidate for spintronic devices such as data storage devices,
and logic-based devices. These skyrmions have distinct properties and interactions, that can be
utilized to control their movement by applying an external electric current. In this work, we have
successfully demonstrated the operation of skyrmion-based universal NAND and NOR logic gates.
We have further performed arithmetic addition of two and three single-bit by using a half and
full adder, fabricated based on the XOR and AND gates. We have observed that the presence of
only uniform Dzyaloshinskii-Moriya interaction is not enough to achieve all logic operations. The
presence of a negative Dzyaloshinskii-Moriya interaction at the edges is crucial in achieving proper
logic operations. The findings are very important for the realization of skyrmion-based logic and
computational operations.