Room-Temperature Skyrmion Shift Device for Memory Application

Abstract

Magnetic skyrmions are intensively explored for potential applications in ultralow-energy data storage and computing. To create practical skyrmionic memory devices, it is necessary to electrically create and manipulate these topologically protected information carriers in thin films, thus realizing both writing and addressing functions. Although room-temperature skyrmions have been previously observed, fully electrically controllable skyrmionic memory devices, integrating both of these functions, have not been developed to date. Here, we demonstrate a room-temperature skyrmion shift memory device, where individual skyrmions are controllably generated and shifted using current-induced spin-orbit torques. Particularly, it is shown that one can select the device operation mode in between (i) writing new single skyrmions or (ii) shifting existing skyrmions by controlling the magnitude and duration of current pulses. Thus, we electrically realize both writing and addressing of a stream of skyrmions in the device. This prototype demonstration brings skyrmions closer to real-world computing applications.

B–T phase diagram of Pd/Fe/Ir(111) computed with parallel tempering Monte Carlo

“…Chiral magnetic spin structures, such as magnetic skyrmions [1], have received a lot of interest since they are possible candidates as bits in data storage [2][3][4][5][6]. Magnetic skyrmions are localized non-collinear spin-textures with a unique rotational sense which defines their chirality.…”

An Improved Racetrack Structure for Transporting a Skyrmion

“…Skyrmion-based racetrack memory171819 is expected to have improved storage density and lower energy consumption in comparison with the racetrack memory based on domain walls202122. Many progresses have been made on the dynamics of current-induced skyrmion motion2381423, however, there is still a long way for putting the skyrmion-based racetrack memory to practice. For example, to create, drive and annihilate/destroy the skyrmions or the skyrmion cluster2425 at will is still a challenge.…”

Efficient in-line skyrmion injection method for synthetic antiferromagnetic systems

“…In figure 4, we demonstrate the writing of two skyrmions followed by a shift operation and finally the deletion of the first skyrmion. While the nucleation and manipulation of only two skyrmions was demonstrated, the proposed device has a storage capacity that is similar to the well-studied skyrmion racetrack memory devices [1,2,5,7,12,35]. Skyrmion shifting is achieved by the application of a current density along the axis of the nanowire.…”

“…Magnetic skyrmions are bubble-like magnetization configurations that exist in the nanometer length scale. Due to their many attractive attributes as a candidate for a universal memory, they have been at the center of much scientific endeavors [1][2][3][4][5][6][7]. However, a few persistent challenges hinder the realization of the skyrmionic memory.…”