混合拓扑双半子簇的稳定性与电流驱动动力学
Stability and current-driven dynamics of mixed-topology bimeron clusters
- University of Luxembourg（卢森堡大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过测地线微推弹性带和Thiele方法，分析混合拓扑双半子簇的稳定性与电流驱动动力学，发现其速度位于由哈密顿量决定的椭圆上。
AI中文摘要：
在本工作中，我们研究了双半子（面内斯格明子）及其由混合拓扑指数态组成的簇。这些簇为控制斯格明子霍尔角提供了灵活性，该角度取决于簇的总拓扑电荷。首先，利用最简单的此类簇——双半子-反双半子对，我们通过测地线微推弹性带方法检验其稳定性，并识别出三种机制——双半子分离、互换和湮灭——它们具有相当的能量势垒，决定了该对的整体稳定性。这为更复杂的双半子和反双半子簇的稳定性提供了上限。然后，我们数值研究了在面内和垂直于平面的电流下簇的动力学，分别对应Zhang-Li和Slonczewski机制。最后，我们在Thiele方法框架内分析了多种双半子簇的动力学，并表明它们的速度总是位于一个特定的椭圆上，该椭圆的参数完全由模型哈密顿量决定。
英文摘要：
In this work, we study bimerons (in-plane skyrmions) and their clusters composed of states with mixed topological indices. These clusters provide flexibility in controlling the skyrmion Hall angle, which depends on the cluster's total topological charge. First, using the simplest such cluster, a bimeron-antibimeron pair, we examine its stability with the geodesic nudged elastic band method and identify three mechanisms -- bimeron separation, interchange, and annihilation -- with comparable energy barriers that determine the pair's overall stability. This provides an upper bound for the stability of more sophisticated clusters of bimerons and antibimerons. Then, we numerically study the clusters' dynamics for currents applied in-plane and perpendicular to the plane, corresponding to the Zhang-Li and Slonczewski mechanisms. Finally, we analyze the dynamics of a wide variety of bimeron clusters within the Thiele approach and show that their velocities always lie on a specific ellipse whose parameters are fully governed by the model Hamiltonian.
