This book provides a comprehensive overview of the latest developments in the field of spin dynamics and magnetic damping. It discusses the various ways to tune damping, specifically, dynamic and static control in a ferromagnetic layer/heavy metal layer. In addition, it addresses all optical detection techniques for the investigation of modulation of damping, for example, the time-resolved magneto-optical Kerr effect technique.

Ultrafast magnetization dynamics describe the physics of a magnetic system on the perturbation by a strong laser pulse. This pulse excites the electrons close to the Fermi energy. It is followed by a thermalization due to a variety of scattering processes. The plenitude of these processes is of fundamental interest for solid states physics, but isnot yet understood properly. In the field of ultrafast magnetization dynamics most progress was achieved by all optical measurements. However, the interpretation of all optical experiments is still under debate. In order to gain direct insight into the time evolution of the spin polarization a time and spin-resolved pump-probe experiment is applied. This allows one to measure the quenching of the spin polarization without any optical contributions. In our experiment the spin polarization of the photoexcited electrons of in situ prepared thin Fe and Co films is measured directly with a Mott-detector. The overall signal shape matches the one of the all optical measurements. Thus, with the help of our measurements it could thus be shown, that the all optical techniques indeed contain a contribution of magnetic origin.

This second volume of the book on spin dynamics in confined magnetic structures covers central aspects of spin dynamic phenomena, so that researchers can find a comprehensive compilation of the current work in the field. Introductory chapters help newcomers to understand the basic concepts, and the more advanced chapters give the current state of the art for most spin dynamic issues in the milliseconds to femtoseconds range. Both experimental techniques and theoretical work are discussed. The comprehensive presentation of these developments makes this volume very timely and valuable for every researcher working in the field of magnetism. It describes the new experimental techniques which have advanced this field very rapidly. Among the techniques covered, particular attention is given to those involving high temporal, elemental and spatial resolution as well as to techniques involving magnetic field pulses with very short rise times and durations.

Introductory chapters help newcomers to understand the basic concepts, and the more advanced chapters give the current state of the art for most spin dynamic issues in the milliseconds to femtoseconds range. Emphasis is placed on both the discussion of the experimental techniques and on the theoretical work. The comprehensive presentation of these developments makes this volume very timely and valuable for every researcher working in the field of magnetism.

This volume on Ultrafast Magnetism is a collection of articles presented at the international “Ultrafast Magnetization Conference” held at the Congress Center in Strasbourg, France, from October 28th to November 1st, 2013. This first conference, which is intended to be held every two years, received a wonderful attendance and gathered scientists from 27 countries in the field of Femtomagnetism, encompassing many theoretical and experimental research subjects related to the spins dynamics in bulk or nanostructured materials. The participants appreciated this unique opportunity for discussing new ideas and debating on various physical interpretations of the reported phenomena. The format of a single session with many oral contributions as well as extensive time for poster presentations allowed researchers to have a detailed overview of the field. Importantly, one could sense that, in addition to studying fundamental magnetic phenomena, ultrafast magnetism has entered in a phase where applied physics and engineering are playing an important role. Several devices are being proposed with exciting R&D perspectives in the near future, in particular for magnetic recording, time resolved magnetic imaging and spin polarized transport, therefore establishing connections between various aspects of modern magnetism. Simultaneously, the diversity of techniques and experimental configurations has flourished during the past years, employing in particular Xrays, visible, infra-red and terahertz radiations. It was also obvious that an important effort is being made for tracking the dynamics of spins and magnetic domains at the nanometer scale, opening the pathway to exciting future developments. The concerted efforts between theoretical and experimental approaches for explaining the dynamical behaviors of angular momentum and energy levels, on different classes of magnetic materials, are worth pointing out. Finally it was unanimously recognized that the quality of the scientific oral and poster presentations contributed to bring the conference to a very high international standard.