Atomic and nanoscale spin dynamics

Abstract The relationship between quantum mechanics and nanoscale spin dynamics is investigated by analyzing past work in magnetism and beyond. Findings about magnetization dynamics, accumulated throughout the 20th century, are revisited from a unifying modern perspective and related to trends in other areas of physics and technology. Traditional topics, for example spin precession and thermally activated magnetization processes, are discussed with emphasis on characteristic times and length scales, showing that nanoscale magnetization dynamics is very different from atomic spin dynamics. It is shown how these topics are connected to more recent developments such as the Berry phase, the no-cloning theorem, quantum-spin fluctuations, and THz magnetization dynamics in antiferromagnets.