Emergent electrodynamics of topological spin textures

skyrmions中磁化的非平凡拓扑缠绕和相关的拓扑自旋织构产生了与自旋电流的极其有效的耦合，这可以用紧急电动力学的术语来优雅地描述。潜在的涌现磁场和电场会产生拓扑霍尔效应，并且在自旋传递扭矩（STT）诱导的自旋织构流动中，会产生一个涌现电场。我们建议在选定的块状材料中对STT驱动的拓扑自旋织构的涌现电动力学进行全面的研究，重点关注拓扑自旋织构在各种条件下的产生、运动和衰减。所提出的研究结合了通过新一代实验室技术获得的输运和热力学信息以及通过新一代中子和x射线散射技术获得的微观信息。前者包括stt下的交流磁化率和磁强计、高分辨率转矩磁强计以及振荡磁场和stt下的电输运特性，后者涉及超高分辨率中子谱学，以及动力学小角中子散射（SANS）、动力学grace入射小角中子散射（GISANS）和共振弹性x射线散射（REXS）。

The non-trivial topological winding of the magnetization in skyrmions and related topological spin textures gives rise to an extremely efficient coupling with spin currents, that may be elegantly described in terms of an emergent electrodynamics. The underlying emergent magnetic and electric fields give rise to a topological Hall effect and, in the presence of spin transfer torque (STT) induced flow of the spin textures, an emergent electric field. We propose to perform comprehensive studies of the emergent electrodynamics in STT driven topological spin textures in selected bulk materials, focusing on the creation, motion and decay of topological spin textures under various conditions. The proposed studies combine transport and thermodynamic information obtained by means of a new generation of laboratory-based techniques with microscopic information obtained by means of a new generation of neutron and x-ray scattering techniques. The former includes ac susceptibility and magnetometry under STTs, high-resolution torque magnetometry, and electrical transport properties under oscillating magnetic fields and STTs, whereas the latter concern ultra-high-resolution neutron spectroscopy, as well as kinetic small angle neutron scattering (SANS), kinetic gracing incidence small angle neutron scattering (GISANS) and resonant elastic x-ray scattering (REXS).