arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1503.03523cond-mat.mes-hall
收藏

拓扑霍尔效应研究MnSi纳米线中Skyrmion的电流驱动动力学

Current-Driven Dynamics of Skyrmions Stabilized in MnSi Nanowires Revealed by Topological Hall Effect

Dong Liang, John P. DeGrave, Matthew J. Stolt, Yoshinori Tokura, Song Jin

摘要:

Skyrmions是一种新型拓扑稳定的自旋涡旋,由于其纳米级结构域可以实现高信息存储密度,并且其电流驱动运动的低阈值可以实现超低能耗,因此为下一代磁存储带来了希望。一维(1D)纳米线是理想的主机skyrmions,因为它们不仅作为一个天然的平台,磁赛道存储设备,但也可以潜在地稳定skyrmions。本文利用拓扑霍尔效应(THE)研究了MnSi纳米线中Skyrmion的相稳定性和电流驱动动力学。在扩展的磁场-温度窗口(15至30 K)中观察到THE,表明与体相(27至29.5 K)相比,纳米线中的skyrmion相稳定。此外,我们第一次研究了在这个扩展的skyrmion相区的skyrmion动力学,发现在高电流密度的$10^{8}-10^{9} Am^{-2}$纳米线的几何形状,随着电流密度的增加,THE降低,这表明电流驱动的skyrmion运动产生的新兴电场。这些结果开辟了探索纳米线作为一个有吸引力的平台,研究skyrmion物理在1D系统和利用skyrmion磁存储概念。

英文摘要:

Skyrmions, novel topologically stable spin vortices, hold promise for next-generation magnetic storage due to their nanoscale domains to enable high information storage density and their low threshold for current-driven motion to enable ultralow energy consumption. One-dimensional (1D) nanowires are ideal hosts for skyrmions since they not only serve as a natural platform for magnetic racetrack memory devices but also can potentially stabilize skyrmions. Here we use the topological Hall effect (THE) to study the phase stability and current-driven dynamics of the skyrmions in MnSi nanowires. The THE was observed in an extended magnetic field-temperature window (15 to 30 K), suggesting stabilization of skyrmion phase in nanowires compared with the bulk (27 to 29.5 K). Furthermore, for the first time, we study skyrmion dynamics in this extended skyrmion phase region and found that under the high current-density of $10^{8}-10^{9} Am^{-2}$ enabled by nanowire geometry, the THE decreases with increasing current densities, which demonstrates the current-driven motion of skyrmions generating the emergent electric field. These results open up the exploration of nanowires as an attractive platform for investigating skyrmion physics in 1D systems and exploiting skyrmions in magnetic storage concepts.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑