TOPSTONE - Topological Solitons In Frustrated Magnets

一维和准二维磁孤子的研究近年来得到了很大的发展，特别是由于对传统（反）铁磁体中畴壁和skyrmions的研究取得了巨大的进展。稳定的三维孤子的检测（例如，然而，在共线磁系统中，由于S^{2}-序参数的性质，hopfions）仍然难以捉摸，因此代表了当今自旋电子学的重大挑战之一。在这个研究项目中，我们的目标是建立磁阻挫系统作为一个新的平台，这些拓扑纹理的创建和操作。这种通用平台带来的优点是，它的序参数流形是由旋转矩阵组提供的，因此，在受抑磁体中的磁孤子/缺陷的性质超越了通常的S^{2}范例。更具体地说，我们的目标是解开和利用这些通用平台的拓扑输运性质，通过构建一个通用的框架，探索突发拓扑孤子的发生，稳定性和动力学。我们将通过以下计划来完成这一具有挑战性的任务：i）我们将为承载（稳定）孤子的受抑磁体构建现实的最小模型，并探索其拓扑弛豫的机制/通道，这反过来又决定了它们的（有限）寿命。ii）我们将发展流体动力学/唯象理论的拓扑电荷和集体（类自旋）自由度的孤子植根于拓扑约束存在于这类材料。iii）基于电学的方法将被用来控制受抑磁体中的磁化和拓扑孤子。特别是，我们将表明，孤子介导的自旋信号传输显示出更大的弹性对退化（代数衰减）比通常的磁振子介导的计划（指数衰减），这提供了有前途的前景，以孤子为基础的计算领域。

The field of one- and (quasi-)two-dimensional magnetic solitons has bloomed in recent years, especially due to the enormous progress made on domain walls and skyrmions in conventional (anti-)ferromagnets. Detection of stable three-dimensional solitons (e.g., hopfions) has, however, remained elusive in collinear magnetic systems due in part to the nature of the S^{2}-order parameter, therefore representing one of the grand challenges of spintronics nowadays. In this research project we aim at establishing magnetically frustrated systems as a new platform for the creation and manipulation of these topological textures. This versatile platform brings the advantage that its order-parameter manifold is provided by the group of rotation matrices and, consequently, the nature of the magnetic solitons/defects in frustrated magnets goes beyond that of the usual S^{2} paradigm. More specifically, our goal is to unravel and exploit the topological transport properties of these versatile platforms by constructing a general framework in which explore the onset, stability and dynamics of the emergent topological solitons. We will accomplish this challenging task by means of the following program: i) we will construct realistic minimal models for frustrated magnets that host (stable) solitons, and explore the mechanisms/channels for their topological relaxation, which, in turn, determine their (finite) lifetimes. ii) We will develop hydrodynamic/phenomenological theories for the topological charge and collective (spin-like) degrees of freedom of solitons rooted in the topological constraints present in this class of materials. iii) Electrically-based approaches will be utilized to control the magnetization and topological solitons in frustrated magnets. In particular, we will show that soliton-mediated transmission of spin signals displays a greater resilience against degradation (algebraic decay) than that of the usual magnon-mediated schemes (exponential decay), which offers promising perspectives to the field of soliton-based computing.