The topic of lattice quantum spin systems is a fascinating and by now well established branch of theoretical physics, although many important questions still remain to be answered. The intrinsic quantum mechanical nature and the large (usually effectively infinite) number of spins in materials lead to often unexpected and indeed counter-intuitive results and insights. As such, beyond being basic models for a whole host of magnetic materials, spin systems are important as prototypical models of quantum systems. Low dimensional systems as treated in this primer, in 2D and especially 1D, have been particularly fruitfulbecause their simplicity has enabled exact solutions to be found which still contain many highly non-trivial features. This book, an outgrow of actual lectures, is at a level of practical detail which is missing in other textbooks inthe area. It will guide any reader, wanting to starting research work in thisarea, through the foundations of the field. In particular, the solutions of the Heisenberg and XY models at zero temperature using the Bethe Ansatz and theJordan-Wigner transformation and approximate methods, both theoretical and numerical, to tackle more advanced topics are introduced and covered in some detail. The final chapter describes some very recent applications, to show some of the directions in which study of these systems currently develops. Very useful as a self-study guide Provides examples and step by step derivations Goes straight to advanced level teachings INDICE: Introduction.- Spin Models.- Quantum Treatment of the Spin-1/2 Chain.- The Antiferromagnetic Ground State.- Antiferromagnetic Spin Waves.- The XY Model.- Spin-Wave Theory.- Numerical Finite-Size Calculations.- Other Approximate Methods.- The Coupled-Cluster Method.- Quantum Magnetism.- Index.
- ISBN: 978-3-642-13289-6
- Editorial: Springer
- Encuadernacion: Rústica
- Páginas: 150
- Fecha Publicación: 01/09/2010
- Nº Volúmenes: 1
- Idioma: Inglés