论文标题

沮丧的铁磁单层中Bimerons的静态和动态特性

Static and dynamic properties of bimerons in a frustrated ferromagnetic monolayer

论文作者

Zhang, Xichao, Xia, Jing, Shen, Laichuan, Ezawa, Motohiko, Tretiakov, Oleg A., Zhao, Guoping, Liu, Xiaoxi, Zhou, Yan

论文摘要

磁性Bimeron是平面磁体中Skyrmions的拓扑对应物,可以用作旋转的信息载体。我们在沮丧的铁磁单层中报告了具有不同拓扑结构的比门龙的静态特性,其中bimeron结构的特征是涡旋$ q _ {\ text {v}} $ and helicity $ $η$。发现Bimeron Energy随着$ Q _ {\ text {v}} $的增加而增加,以及带有$ q _ {\ text {v}} = \ pm 1 $的隔离bimeron的能量取决于$η$。我们还报告了由旋转轨道扭矩驱动的沮丧的Bimerons的动力,这取决于阻尼状的和野外的扭矩的强度。我们发现,当自旋极化垂直于易于轴时,带有$ q _ {\ text {v}} = \ pm 1 $的隔离bimeron可以将其驱动到线性或椭圆运动中。我们在数值上揭示了由阻尼状扭矩驱动的Bimeron Hall角度的阻尼依赖性。此外,当旋转极化与易于轴平行时,带有$ q _ {\ text {v}} = \ pm 1 $的隔离bimeron可以通过阻尼状扭矩旋转。旋转频率与驱动电流密度成正比。此外,我们从数值上证明了通过以当前驱动的碰撞和与不同$ q _ {\ text {v}} $合并的比默隆碰撞并合并Bimeron状态的可能性。我们的结果对于理解沮丧的磁铁的Bimeron物理可能很有用。

Magnetic bimeron is a topological counterpart of skyrmions in in-plane magnets, which can be used as a spintronic information carrier. We report the static properties of bimerons with different topological structures in a frustrated ferromagnetic monolayer, where the bimeron structure is characterized by the vorticity $Q_{\text{v}}$ and helicity $η$. It is found that the bimeron energy increases with $Q_{\text{v}}$, and the energy of an isolated bimeron with $Q_{\text{v}}=\pm 1$ depends on $η$. We also report the dynamics of frustrated bimerons driven by the spin-orbit torques, which depend on the strength of the dampinglike and fieldlike torques. We find that the isolated bimeron with $Q_{\text{v}}=\pm 1$ can be driven into linear or elliptical motion when the spin polarization is perpendicular to the easy axis. We numerically reveal the damping dependence of the bimeron Hall angle driven by the dampinglike torque. Besides, the isolated bimeron with $Q_{\text{v}}=\pm 1$ can be driven into rotation by the dampinglike torque when the spin polarization is parallel to the easy axis. The rotation frequency is proportional to the driving current density. In addition, we numerically demonstrate the possibility of creating a bimeron state with a higher or lower topological charge by the current-driven collision and merging of bimeron states with different $Q_{\text{v}}$. Our results could be useful for understanding the bimeron physics in frustrated magnets.

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