arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.04395cond-mat.mes-hallcond-mat.soft
收藏

Shapiro台阶与直流和交流驱动下二维周期基底上斯格明子的非线性斯格明子霍尔角

Shapiro Steps and Nonlinear Skyrmion Hall Angles For dc and ac Driven Skyrmions on a Two Dimensional Periodic Substrate

N. P. Vizarim, C. Reichhardt, P. A. Venegas, C. J. O. Reichhardt

AI总结:

本文研究直流与交流驱动下二维周期基底上斯格明子的动力学,发现Shapiro台阶与方向锁定相互作用导致多种同步现象,并可通过调节交流振幅控制斯格明子霍尔角。

摘要:

对于在直流和交流联合驱动下在二维周期基底上运动的过阻尼粒子,速度-力曲线中会出现一系列台阶,称为Shapiro台阶。本文表明,对于在直流驱动以及平行或垂直于直流驱动的交流驱动下,在二维周期障碍物阵列上驱动的斯格明子,由于马格努斯力,系统表现出多种横向和纵向同步动力学。这些现象源于两种不同类型的锁相效应之间的相互作用:Shapiro台阶和方向锁定。在某些情况下,斯格明子霍尔角是恒定的,但出现纵向Shapiro台阶;而在其他区域,当斯格明子锁定到障碍物晶格的不同对称方向时,在锁相期间,斯格明子霍尔角可能随着直流驱动的增加而增大或减小。对于横向交流驱动,我们发现在某些锁定相中会出现强烈的霍尔角过冲,此时斯格明子以远大于固有霍尔角的角度运动。对于最强的马格努斯力,锁相效应减弱,无序动力学区域增大。我们表明,通过固定直流驱动并改变交流驱动的振幅,可以控制斯格明子霍尔角。

英文摘要:

For an overdamped particle moving over a two-dimensional periodic substrate under combined dc and ac drives, a series of steps can appear in the velocity force curves that are known as Shapiro steps. Here we show that for skyrmions driven over a two-dimensional periodic obstacle array with a dc drive and an ac drive that is either parallel or perpendicular to the dc drive, the system exhibits numerous transverse and longitudinal synchronization dynamics due to the Magnus force. These phenomena originate in interactions between two different types of phase locking effects: Shapiro steps and directional locking. In some cases, the skyrmion Hall angle is constant but longitudinal Shapiro steps appear, while in other regimes the skyrmion Hall angle can either increase or decrease with increasing dc drive during the phase locking as the skyrmion locks to different symmetry directions of the obstacle lattice. For a transverse ac drive we find that strong Hall angle overshoots can occur in certain locked phases where the skyrmion is moving at an angle that is considerably larger than the intrinsic Hall angle. For the strongest Magnus force, the phase locking effects are reduced and there are larger regions of disordered dynamics. We show that the skyrmion Hall angle can be controlled by fixing the dc drive and changing the amplitude of the ac drive.

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。

↑