arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2005.11924cond-mat.mes-hall
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自旋流和磁场驱动下铁磁双分子的动力学

Dynamics of ferromagnetic bimerons driven by spin currents and magnetic fields

Laichuan Shen, Xiaoguang Li, Jing Xia, Lei Qiu, Xichao Zhang, Oleg A. Tretiakov, Motohiko Ezawa, Yan Zhou

摘要:

磁双重子是面内磁体中磁skyrmion的拓扑对应物,可作为自旋电子器件中的非易失性信息载体。本文用解析和数值方法研究了自旋电流和磁场作用下铁磁双分子的动力学行为。数值模拟结果表明,在铁磁薄膜中,通过电流诱导的自旋力矩可以同时产生两个拓扑数符号相反的双分子。电流感应自旋力矩也能驱动双片体,并推导了双片体的速度,与数值计算结果一致。由于具有相反拓扑数的双分子可以共存并且具有相反的漂移方向,因此可以构建双通道赛道以准确地编码数据比特。此外,还研究了梯度磁场和交变磁场作用下的双分子动力学。发现在交变磁场作用下,双重子可以沿一定方向传播。此外,结合适当的磁场梯度,马格努斯力诱导的横向运动可以被完全抑制,这意味着不存在Skyrmion霍尔效应。我们的研究结果是有用的双分子动力学的理解,并可能为未来的双分子为基础的自旋电子器件的建设提供指导。

英文摘要:

Magnetic bimeron composed of two merons is a topological counterpart of magnetic skyrmion in in-plane magnets, which can be used as the nonvolatile information carrier in spintronic devices. Here we analytically and numerically study the dynamics of ferromagnetic bimerons driven by spin currents and magnetic fields. Numerical simulations demonstrate that two bimerons with opposite signs of topological numbers can be created simultaneously in a ferromagnetic thin film via current-induced spin torques. The current-induced spin torques can also drive the bimeron and its speed is analytically derived, which agrees with the numerical results. Since the bimerons with opposite topological numbers can coexist and have opposite drift directions, two-lane racetracks can be built in order to accurately encode the data bits. In addition, the dynamics of bimerons induced by magnetic field gradients and alternating magnetic fields are investigated. It is found that the bimeron driven by alternating magnetic fields can propagate along a certain direction. Moreover, combining a suitable magnetic field gradient, the Magnus-force-induced transverse motion can be completely suppressed, which implies that there is no skyrmion Hall effect. Our results are useful for understanding of the bimeron dynamics and may provide guidelines for building future bimeron-based spintronic devices.

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。

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