Thermal Fluctuations And Relaxation Processes In Nanomagnets

Download or read book Thermal Fluctuations And Relaxation Processes In Nanomagnets written by William T Coffey and published by World Scientific. This book was released on 2020-05-21 with total page 709 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting in a coherent and accessible fashion current results in nanomagnetism, this book constitutes a comprehensive, rigorous and readable account, from first principles of the classical and quantum theories underlying the dynamics of magnetic nanoparticles subject to thermal fluctuations.Starting with the Larmor-like equation for a giant spin, both the stochastic (Langevin) equation of motion of the magnetization and the associated evolution (Fokker-Planck) equation for the distribution function of the magnetization orientations of ferromagnetic nanoparticles (classical spins) in a heat bath are developed along with their solution (using angular momentum theory) for arbitrary magnetocrystalline-Zeeman energy. Thus, observables such as the magnetization reversal time, relaxation functions, dynamic susceptibilities, etc. are calculated and compared with the predictions of classical escape rate theory including in the most general case spin-torque-transfer. Regarding quantum effects, which are based on the reduced spin density matrix evolution equation in Hilbert space as is described at length, they are comprehensively treated via the Wigner-Stratonovich formulation of the quantum mechanics of spins via their orientational quasi-probability distributions on a classically meaningful representation space. Here, as suggested by the relevant Weyl symbols, the latter is the configuration space of the polar angles. Hence, one is led, by mapping the reduced density matrix equation onto that space, to a master equation for the quasi-probability evolution akin to the Fokker-Planck equation which may be solved in a similar way. Thus, one may study in a classical-like manner the evolution of observables with spin number ranging from an elementary spin to molecular clusters to the classical limit, viz. a nanoparticle. The entire discussion hinges on the one-to-one correspondence between polarization operators in Hilbert space and the spherical harmonics allied to concepts of spin coherent states long familiar in quantum optics.Catering for the reader with only a passing knowledge of statistical and quantum mechanics, the book serves as an introductory text on a complicated subject where the literature is remarkably sparse.

Download or read book Thermal Fluctuations And Relaxation Processes In Nanomagnets written by William T. Coffey and published by . This book was released on 2020 with total page 709 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanobiomaterials written by Dong Kee Yi and published by CRC Press. This book was released on 2013-08-14 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a continuous exchange of ideas taking place at the border of the biological and physical sciences in many areas of nanoscience. Nanotechnology uses biomimetic or bio-inspired processes to produce nanosized materials for applications in biology and other fields. In return, the fruits of nanotechnology are applied to expanding areas of biomedical and therapeutic processes, such as new nanostructures and scaffolds for tissue engineering or targeted drug delivery. In this way, nanobiotechnology serves as a bridge between nano and bio, with nanoscale materials providing the building blocks for the construction of the "bridge." Nanobiomaterials: Development and Applications gives you a broad, interdisciplinary view of current developments as well as new findings and applications in bionanomaterials. The book brings together the work of international contributors who are actively engaged at the forefront of research in their respective disciplines. Organized into four parts, this book explores the preparation and characterization of nanomaterials, new preparation routes of soft nanomaterials using biomolecules, nano- and microscale hybridization of materials, and nanotoxicity. The contributors cover a diverse set of topics, including: Biomimetic synthesis Bioimaging and cancer diagnosis Photodynamic therapy Bioconjugated carbon nanotube DNA transfection and tumor targeting Magnetically induced hyperthermia Cytotoxity mechanisms and their potential use in therapy Virus-enabled manufacturing of functional nanomaterials Biocatalitic nanosystems and enzyme immobilization Tissue engineering The fabrication of hybrid microswimmers Bionanomaterial applications in environmental remediation Each chapter is richly illustrated and includes an extensive list of references to guide you toward further research. Combining bionanomaterial development and applications, the book clearly demonstrates the importance of these materials to biotechnology, biomedicine, and environmental remediation. It offers an accessible overview for students, industrial researchers, pharmaceutical innovators, medical and public health personnel, environmental scientists and engineers, and anyone interested in this interdisciplinary field.

Download or read book Spintronics written by Jean-Philippe Ansermet and published by CRC Press. This book was released on 2024-08-13 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt: A sound understanding of magnetism, transport theory, spin relaxation mechanisms, and magnetization dynamics is necessary to engage in spintronics research. In this primer, special effort has been made to give straightforward explanations for these advanced concepts. This book will be a valuable resource for graduate students in spintronics and related fields. Concepts of magnetism such as exchange interaction, spin-orbit coupling, spin canting, and magnetic anisotropy are introduced. Spin-dependent transport is described using both thermodynamics and Boltzmann’s equation, including Berry curvature corrections. Spin relaxation phenomenology is accounted for with master equations for quantum spin systems coupled to a bath. Magnetic resonance principles are applied to describe spin waves in ferromagnets, cavity-mode coupling in antiferromagnets, and coherence phenomena relevant to spin qubits applications. Key Features: • A pedagogical approach to foundational concepts in spintronics with simple models that can be calculated to enhance understanding. • Nineteen chapters, each beginning with a historical perspective and ending with an outlook on current research. • 1200 references, ranging from landmark papers to frontline publications. Jean-Philippe Ansermet is Professor Emeritus at École Polytechnique Fédérale de Lausanne (EPFL), where he pioneered experiments on giant magnetoresistance, current-induced magnetization switching, heat-driven spin torque, and nuclear magnetic resonance. He taught mechanics, thermodynamics, and spin dynamics for more than twenty years. A fellow of the American Physical Society and recipient of the 2022 Credit Suisse Teaching Award, he was an executive board member of the European Physical Society, president of the Swiss Physical Society, and teaching director at EPFL. He has authored or co-authored textbooks on mechanics and thermodynamics and published more than two hundred articles.

Download or read book Langevin Equation, The: With Applications To Stochastic Problems In Physics, Chemistry And Electrical Engineering (Fourth Edition) written by William T Coffey and published by World Scientific. This book was released on 2017-03-22 with total page 927 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our original objective in writing this book was to demonstrate how the concept of the equation of motion of a Brownian particle — the Langevin equation or Newtonian-like evolution equation of the random phase space variables describing the motion — first formulated by Langevin in 1908 — so making him inter alia the founder of the subject of stochastic differential equations, may be extended to solve the nonlinear problems arising from the Brownian motion in a potential. Such problems appear under various guises in many diverse applications in physics, chemistry, biology, electrical engineering, etc. However, they have been invariably treated (following the original approach of Einstein and Smoluchowski) via the Fokker-Planck equation for the evolution of the probability density function in phase space. Thus the more simple direct dynamical approach of Langevin which we use and extend here, has been virtually ignored as far as the Brownian motion in a potential is concerned. In addition two other considerations have driven us to write this new edition of The Langevin Equation. First, more than five years have elapsed since the publication of the third edition and following many suggestions and comments of our colleagues and other interested readers, it became increasingly evident to us that the book should be revised in order to give a better presentation of the contents. In particular, several chapters appearing in the third edition have been rewritten so as to provide a more direct appeal to the particular community involved and at the same time to emphasize via a synergetic approach how seemingly unrelated physical problems all involving random noise may be described using virtually identical mathematical methods. Secondly, in that period many new and exciting developments have occurred in the application of the Langevin equation to Brownian motion. Consequently, in order to accommodate all these, a very large amount of new material has been added so as to present a comprehensive overview of the subject.

Download or read book Oxford Handbook of Nanoscience and Technology written by A.V. Narlikar and published by Oxford University Press, USA. This book was released on 2010-02-11 with total page 931 pages. Available in PDF, EPUB and Kindle. Book excerpt: These three volumes are intended to shape the field of nanoscience and technology and will serve as anessential point of reference for cutting-edge research in the field.

Download or read book Fluctuations and Noise in Biological, Biophysical, and Biomedical Systems written by Sergey M. Bezrukov and published by SPIE-International Society for Optical Engineering. This book was released on 2003 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: