Dynamics Of Topological Magnetic Solitons

Dynamics of Topological Magnetic Solitons gives a theoretical and experimental review of the dynamics of high-speed domain walls and Bloch lines. After the introduction of magnetic solitons, experimental methods for the observation of the dynamics of domain walls are presented. Further chapters discuss main features of the stimulated motion of domain walls, their magnetoelastic interaction, stability and relaxation. Finally, the dynamics of domain walls in weak ferromagnets with more than one dimension is treated. The last chapter presents the dynamics of Bloch lines and their clusters. More than 230 references guide the reader to the literature. Physicists will gain new insights in interesting applications of soliton theory in condensed matter physics. Engineers will find new information on magnetooptical effects for further applications.

This text focuses on conservation laws in magnetohydrodynamics, gasdynamics and hydrodynamics. A grasp of new conservation laws is essential in fusion and space plasmas, as well as in geophysical fluid dynamics; they can be used to test numerical codes, or to reveal new aspects of the underlying physics, e.g., by identifying the time history of the fluid elements as an important key to understanding fluid vorticity or in investigating the stability of steady flows. The ten Galilean Lie point symmetries of the fundamental action discussed in this book give rise to the conservation of energy, momentum, angular momentum and center of mass conservation laws via Noether’s first theorem. The advected invariants are related to fluid relabeling symmetries – so-called diffeomorphisms associated with the Lagrangian map – and are obtained by applying the Euler-Poincare approach to Noether’s second theorem. The book discusses several variants of helicity including kinetic helicity, cross helicity, magnetic helicity, Ertels’ theorem and potential vorticity, the Hollman invariant, and the Godbillon Vey invariant. The book develops the non-canonical Hamiltonian approach to MHD using the non-canonical Poisson bracket, while also refining the multisymplectic approach to ideal MHD and obtaining novel nonlocal conservation laws. It also briefly discusses Anco and Bluman’s direct method for deriving conservation laws. A range of examples is used to illustrate topological invariants in MHD and fluid dynamics, including the Hopf invariant, the Calugareanu invariant, the Taylor magnetic helicity reconnection hypothesis for magnetic fields in highly conducting plasmas, and the magnetic helicity of Alfvén simple waves, MHD topological solitons, and the Parker Archimedean spiral magnetic field. The Lagrangian map is used to obtain a class of solutions for incompressible MHD. The Aharonov-Bohm interpretation of magnetic helicity and cross helicity is discussed. In closing, examples of magnetosonic N-waves are used to illustrate the role of the wave number and group velocity concepts for MHD waves. This self-contained and pedagogical guide to the fundamentals will benefit postgraduate-level newcomers and seasoned researchers alike.

Solitons were discovered by John Scott Russel in 1834, and have interested scientists and mathematicians ever since. They have been the subject of a large body of research in a wide variety of fields of physics and mathematics, not to mention engineering and other branches of science such as biology. This volume comprises the written versions of the talks presented at a workshop held at Queen's University in 1997, an interdisciplinary meeting wherein top researchers from many fields could meet, interact, and exchange ideas. Topics covered include mathematical and numerical aspects of solitons, as well as applications of solitons to nuclear and particle physics, cosmology, and condensed-matter physics. The book should be of interest to researchers in any field in which solitons are encountered.

Dynamics of Topological Magnetic Solitons gives a theoretical and experimental review of the dynamics of high-speed domain walls and Bloch lines. After the introduction of magnetic solitons, experimental methods for the observation of the dynamics of domain walls are presented. Further chapters discuss main features of the stimulated motion of domain walls, their magnetoelastic interaction, stability and relaxation. Finally, the dynamics of domain walls in weak ferromagnets with more than one dimension is treated. The last chapter presents the dynamics of Bloch lines and their clusters. More than 230 references guide the reader to the literature. Physicists will gain new insights in interesting applications of soliton theory in condensed matter physics. Engineers will find new information on magnetooptical effects for further applications.

Magnonics, a research field that uses spin waves, collective excitations of ordered magnetic materials, or magnons (their quanta) as a tool for signal processing, communication, and computation, has rapidly grown during the past decade because of the low-energy consumption and potential compatibility with next-generation circuits beyond CMOS electronics. The interest in 3D magnonic nanostructures follows the latest trend in conventional electronics based on expansion from 2D planar to 3D vertically integrated structures. To remain on the same technological level, a similar expansion should be realized in magnonics. Following this trend, this book provides an overview of recent developments in the exploitation of the third dimension in magnonics, with special focus on the propagation of spin waves in layered magnonic crystals, spin textures, curved surfaces, 3D nano-objects, and cavity magnonics.

This is the first book providing overview of magnetism in curved geometries, highlighting numerous peculiarities emerging from geometrically curved magnetic objects such as curved wires, shells, as well as complex three-dimensional structures. Extending planar two-dimensional structures into the three-dimensional space has become a general trend in multiple disciplines across electronics, photonics, plasmonics and magnetics. This approach provides the means to modify conventional and even launch novel functionalities by tailoring the local curvature of an object. The book covers the theory of curvilinear micromagnetism as well as experimental studies of geometrically curved magnets including both fabrication and characterization. With its coverage of fundamental aspects, together with exploration of numerous applications across magnonics, bio-engineering, soft robotics and shapeable magnetoelectronics, this edited collection is ideal for all scientists in academia and industry seeking an overview and wishing to keep abreast of advances in the novel field of curvilinear micromagnetism. It provides easy but comprehensive access to the field for newcomers, and can be used for graduate-level courses on this subject.

Single-electron tunneling (SET) and related phenomena have recently come to be considered as "hot topics". This also became apparent when we organized the 4th International Conference on Superconducting and Quantum Effect Devices and Their Applications, SQUID'91, which was held June 18-21, 1991, in Berlin, Germany. Impressed by the number of contributions dedicated to the new physics of ultrasmall devices, we deemed it appropriate to devote this volume of the Springer Series in Electronics and Photonics to these specialized proceedings. The other contributions presented at SQUID'91, which are more conventional in character but nevertheless contain excitingly innovative results, are published separately as Volume 64 of the series Springer Proceedings in Physics. At first glance it seems strange that a conference abbreviated SQUID'91 should attract so many papers on non-superconducting devices, and in fact the first SQUID'XX conferences dealt exclusively with the physics and technology of Josephson junctions, SQUIDs and other superconducting devices and their ap plications. However, many concepts developed for superconducting devices, like tunneling, flux quantization, and flux-charge conjugation, appeared to be suitable for ultrasmall non-superconducting structures as well, and many researchers in the field of superconducting devices extended their activities accordingly. Thus the extension of the conference programme evolved quite informally. Meanwhile, the meetings established themselves as well-known conference series tradition ally appreciated by the SQUID community for its balanced mixture of physics and technology, review and preview. SQUID'XX became a kind of a trademark.