Dzyaloshinskii-Moriya Interactions of Skyrmions for Memory and Logic Devices

Abstract

A skyrmion is considered to be a swirling quasi-particle that can exhibit nano-size disturbances similar to those by a knot of twisting magnetic field lines. The "tangles" observed in the magnetic field lines usually generate very strong localized magnetic fields. Thus, a stable skyrmion represent the smallest realizable ideal element with a magnetic texture while an antiskyrmion is considered to be a localized magnetic particle that represents a non-trivial magnetization texture with a specified magnitude with opposite topological charge to that of a skyrmion. The demand for novel memory and logic devices has grown in recent days with the advancement of communication and information technology. Particular attention has been drawn to the use of skyrmions and antiskyrmions in memory access and storage. The findings in most recent laboratory observation at room temperature further encourage more studies mainly covering transport and dynamic properties of both skyrmions and antiskyrmions. So far, some investigations have pointed on skyrmions for reservoir computing applications which in most applications require very large memory storages and fast access capabilities. To attain this scientific dream, a very careful ferromagnetic material re-engineering on the possibility of annihilating a skyrmion by an antiskyrmion (pairwise) to develop new concepts that may be useful for memory and logic applications. It is only recently that material physicists proposed skyrmions for ultra-dense magnetic memories though it has not been implemented. In this paper, we present the model, simulation and discuss the findings obtained by simulating a magnetic skyrmion model. These magnetic skyrmions were stabilized by Dzyaloshinskii-Moriya interaction. They were analyzed as tiny whirls of magnetic configurations that exhibit memory or logic element characteristics depending on complexity of their logical element geometry. The findings suggested that a magnetic skyrmion with antiskyrmion has a capacity to act as memory element. As a result, adopting them for memory applications can simplify the fabrication process of logic elements if their magnetic spin textures are taken into account. These findings form a promising pointer for future application of skyrmion and antiskyrmion for memory, logic and reservoir computing applications.