An Improved Racetrack Structure for Transporting a Skyrmion.
An Improved Racetrack Structure for Transporting a Skyrmion.
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DOI：
10.1038/srep45330
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发表时间：
2017-03-30
影响因子：
4.6
通讯作者：
Zhou Y
中科院分区：
文献类型：
--
作者：
Lai P;Zhao GP;Tang H;Ran N;Wu SQ;Xia J;Zhang X;Zhou Y
磁天桥具有稳定性好、体积小、驱动电流极低等优点，是下一代数据存储的理想构建块，可以代替传统的磁畴壁在金属跑道存储器中以数据比特的形式存储信息。然而，由于马格努斯力，Skyrmions可能会偏离电子流动的方向，因此可能会在赛道边缘湮灭，导致信息丢失。这里，我们提出了一种新的天米子轨道结构，通过在边缘添加高K材料(具有高磁性晶体各向异性的材料)，有效地将天米子限制在金属轨道的中心区域。根据我们的微磁模拟，这种设计可以克服天空微子的堵塞和湮灭，而在小驱动电流和大驱动电流下，天空微子在跑道上运动时通常会发生这种情况。计算并给出了不同电流密度和不同轨边宽度时，天柱在跑道上运动的相图，结果表明，在较小的驱动电流下，天柱可以在跑道上以较高的速度(约300 m/S)驱动。这种设计为建造一种超高速、高能效的天际离子传输设备提供了可能性。
Magnetic skyrmions are promising building blocks for next generation data storage due to their stability, small size and extremely low currents to drive them, which can be used instead of traditional magnetic domain walls to store information as data bits in metalic racetrack memories. However, skyrmions can drift from the direction of electron flow due to the Magnus force and thus may annihilate at the racetrack edges, resulting in the loss of information. Here we propose a new skyrmion-based racetrack structure by adding high-K materials (materials with high magnetic crystalline anisotropy) at the edges, which confines the skyrmions in the center region of the metalic racetrack efficiently. This design can overcome both the clogging and annihilation of skyrmions according to our micromagnetic simulation, which occur normally for skyrmions moving on a racetrack under small and large driving currents, respectively. Phase diagrams for skyrmion motion on the proposed racetrack with various values of current density and racetrack edge width have been calculated and given, showing that skyrmions can be driven at a high speed (about 300 m/s) in the racetrack under relatively smaller driving currents. This design offers the possiblity of building an ultrafast and energy-efficient skyrmion transport device.