  Magnetic skyrmion, vortex-like swirling topologically stable spin
configurations, is appealing as information carrier for future nanoelectronics,
owing to the stability, small size and extremely low driving current density.
One of the most promising applications of skyrmion is to build racetrack memory
(RM). Compared to domain wall-based RM (DW-RM), skyrmion-based RM (Sky-RM)
possesses quite a few benefits in terms of energy, density and speed etc. Until
now, the fundamental behaviors, including nucleation/annihilation, motion and
detection of skyrmion have been intensively investigated. However, one
indispensable function, i.e., pinning/depinning of skyrmion still remains an
open question and has to be addressed before applying skyrmion for RM.
Furthermore, Current research mainly focuses on physical investigations,
whereas the electrical design and evaluation are still lacking. In this work,
we aim to promote the development of Sky-RM from fundamental physics to
realistic electronics. First, we investigate the pinning/depinning
characteristics of skyrmion in a nanotrack with the voltage-controlled magnetic
anisotropy (VCMA) effect. Then, we propose a compact model and design framework
of Sky-RM for electrical evaluation. This work completes the elementary memory
functionality of Sky-RM and fills the technical gap between the physicists and
electronic engineers, making a significant step forward for the development of
Sky-RM.
