A strategy for the design of magnetic memories in bubble-hosting magnets

Applied Physics Letters, Volume 118, Issue 12, March 2021. Magnetic memories based on localized magnetic objects with high performance are potentially applicable to future memory devices. In such devices, binary data bits “1” and “0” are suggested to be represented by skyrmions or skyrmion bubbles and ferromagnetic gaps, respectively. However, thermal fluctuations and interactions between skyrmions can induce interruptions in the stored data, and additional pinning sites must be fabricated. Here, we suggest that a pinning site-free magnetic memory, called skyrmion-bubble-based memory, can be realized in bubble-hosting magnets. In skyrmion-bubble-based memory, topologically trivial bubbles are used to replace ferromagnetic gaps to represent the other binary bits. A data bitstream can, thus, be represented by a skyrmion-bubble chain, and interactions between two neighbored magnetic objects can naturally suppress undesired motion of data bits. Further, a single skyrmion-bubble chain representing a data bitstream is realized experimentally in a typical bubble-hosting material, Fe3Sn2 nanostripe.