磁性斯格明子的赛道存储

Skyrmions-based magnetic racetrack memory

磁性斯格明子是拓扑稳定的自旋结构,它的尺寸小,驱动电流阈值小,被广泛认为是下一代磁性存储的基本单元.斯格明子的主要优势在于它奇特的动力学性质,特别是它能够与传导电子相互作用,在低电流密度驱动下可以在赛道上稳定地运动.本文结合磁性斯格明子赛道存储的最新研究成果,对斯格明子在赛道上的写入、驱动和读出三个方面进行了较为详细的综述.重点介绍了注入自旋极化电流这一最常见的驱动方法,分析了斯格明子在赛道上的堵塞和湮没现象,探讨了斯格明子霍尔效应及其可能造成信号丢失的危害和相关的解决方法,并在此基础上详细介绍了几种斯格明子塞道存储的优化设计方案.最后总结了磁性斯格明子赛道存储面临的一些挑战.

Magnetic skyrmions are topologically stable spin configurations with small size, which can be driven into motion by a small current. They are widely regarded as building blocks for next-generation magnetic storage. The main advantage of skyrmions lies in their particular dynamic behaviors, especially in their ability to move stably in racetrack under the action of small spin-polarized currents. The writing, driving and reading methods of skyrmions in racetrack are reviewed in detail in this paper, including the most recent research findings. The review focuses on the most commonly used driving method, i.e., driving skyrmions by applying spin-polarized currents. The clogging and annihilation of skyrmions in racetrack are analyzed, with the skyrmion Hall effect discussed which may lead skyrmion signals to lose. Methods to avoid skyrmion Hall effect are introduced and hence the optimized designs for skyrmion-based racetrack are also reviewed. Finally, some challenges of skyrmion-based racetrack memory are discussed.