Magnetism primarily describes the physics and materials science of systems presenting a magnetization -- a macroscopic order parameter characterizing electron angular momentum. The order parameter is associated with the electronic exchange interactions, which is fundamentally quantum mechanical. Its dynamic behavior bridges the macroscopic and the microscopic worlds. On macroscopic length and time-scales, it interacts with electromagnetic fields dictated by the Maxwells equations. On a microscopic scale, it involves the quantum-mechanical electronic states both in spin-space and momentum space, thus giving rise to a wide range of behavior that extend down to femtoseconds. Thanks to the development of modern metrology, there have been many new and noteworthy observations of magnetism-related phenomena across the entire range -- from spin-torque induced antidamping dynamics, to ultrafast laser induced femtosecond electron dynamics that involve spin current and angular momentum conservation. In this review we introduce some observations on magnetodynamics, and the scientific subjects these new results give rise to.
Magnetism Induced by Periodically Driven Non-Magnetic Impurities on Surfaces with Spin-Orbit Coupling
Universidad del País Vasco UPV/EHU（巴斯克大学）；Centro de Física de Materiales (CFM/MPC) CSIC-UPV/EHU（巴斯克材料物理中心）；Donostia International Physics Center (DIPC)（圣塞巴斯蒂安国际物理中心）；EHU Quantum Center（巴斯克大学量子中心）
Magnetism and Topology from Circularly Polarized Phonon Floquet Engineering
RIKEN Center for Emergent Matter Science (CEMS)（RIKEN 涌现物质科学中心）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）；The Institute for Solid State Physics, The University of Tokyo（东京大学固体物理研究所）；Department of Physics, Institute of Science Tokyo（东京科学大学物理系）
Enhanced Magnetism & Time - Stable Remanence at the Interface of Hematite and Carbon Nanotubes
两种不同材料的界面在凝聚态物质中以惊喜而闻名，并为丰富的物理学提供了途径，也为未来的技术进步提供了种子。我们提出了一些令人兴奋的磁化强度（M）和剩余磁化强度（$μ$）的结果，这最终出现在两个高度功能性的材料，即碳纳米管（CNT）和$α$ -Fe $_2$ O $_3$，一个Dzyaloshinskiii-Moriya相互作用驱动的弱铁磁体（WFM）和压电磁体（PzM）的石墨壳的界面。我们表明，CNT内的封装导致M和相应的$μ$（剩磁的时间稳定部分）的非常显著的增强，专用于WFM相。在室温下，高达70%的场内磁化强度以$μ$的形式保留。碳纳米管的晶格参数在Morin转变处表现出明显的反常，证实了这种新颖的界面效应。对裸$α$ $_2$ O $_3$纳米线的对照实验表明，弱铁磁体如$α$ $_2$ O $_3$就它们的剩磁及其随时间的稳定性而言并不那么弱，并且CNT内的封装导致这些功能性的显著增强.
