This book is the eighth in a series of Proceedings for the S eminaire Poincar e, which is directed towards a large audience of physicists and of mathematicians. The goal of this seminar is to provide up to date information about general topics of great interest in physics. Both the theoretical and experimental aspects are covered, with some historical background. Inspired by the Bourbaki seminar in mathematics in its organization, hence nicknamed "Bourbaphy", this Poincar e SeminarisheldattheInstitutHenriPoincar einParis,withcontributionsprepared inadvance.Particularcareisdevotedtothepedagogicalnatureofthepresentation so as to ful?ll the goal of being readable by a large audience of scientists. This new volume of the Poincar e Seminar series "The Spin" corresponds to the eleventh such Seminar, held on December 8, 2007. It describes how this once mysterious quantum reality called spin has become ubiquitous in modern physics from the most theoretical aspects down to the most practical applications of miniaturizing electronic and computer devices or helping medical diagnosis.

This volume is devoted to Quantum Decoherence with lectures from the Seminaire Poincare, held in November 2005 at the Institute Henri Poincare Paris. The goal of this seminar is to provide up-to-date information about general topics of great interest in physics. Both the theoretical and experimental results are covered, with some historical background. Particular care is devoted to the pedagogical nature of the presentation.

This fourteenth volume in the Poincare Seminar Series is devoted to Niels Bohr, his foundational contributions to understanding atomic structure and quantum theory and their continuing importance today. This book contains the following chapters: - Tomas Bohr, Keeping Things Open; - Olivier Darrigol, Bohr's Trilogy of 1913; -John Heilbron, The Mind that Created the Bohr Atom; - Serge Haroche & Jean-Michel Raimond, Bohr's Legacy in Cavity QED; - Alain Aspect, From Einstein, Bohr, Schroedinger to Bell and Feynman: a New Quantum Revolution?; - Antoine Browaeys, Interacting Cold Rydberg Atoms: A Toy Many-Body System; - Michel Bitbol & Stefano Osnaghi, Bohrs Complementarity and Kants Epistemology. Dating from their origin in lectures to a broad scientific audience these seven chapters are of high educational value. This volume is of general interest to physicists, mathematicians and historians.

This fourteenth volume in the Poincare Seminar Series is devoted to Niels Bohr, his foundational contributions to understanding atomic structure and quantum theory and their continuing importance today. This book contains the following chapters: - Tomas Bohr, Keeping Things Open; - Olivier Darrigol, Bohr's Trilogy of 1913; -John Heilbron, The Mind that Created the Bohr Atom; - Serge Haroche & Jean-Michel Raimond, Bohr's Legacy in Cavity QED; - Alain Aspect, From Einstein, Bohr, Schroedinger to Bell and Feynman: a New Quantum Revolution?; - Antoine Browaeys, Interacting Cold Rydberg Atoms: A Toy Many-Body System; - Michel Bitbol & Stefano Osnaghi, Bohrs Complementarity and Kants Epistemology. Dating from their origin in lectures to a broad scientific audience these seven chapters are of high educational value. This volume is of general interest to physicists, mathematicians and historians.

It has been recognised recently that the strange features of the quantum world could be used for new information transmission or processing functions such as quantum cryptography or, more ambitiously, quantum computing. These fascinating perspectives renewed the interest in fundamental quantum properties and lead to important theoretical advances, such as quantum algorithms and quantum error correction codes. On the experimental side, remarkable advances have been achieved in quantum optics, solid state physics or nuclear magnetic resonance. This book presents the lecture notes of the Les Houches Summer School on 'Quantum entanglement and information processing'. Following the long tradition of the les Houches schools, it provides a comprehensive and pedagogical approach of the whole field, written by renowned specialists.
One major goal of this book is to establish connections between the communities of quantum optics and of quantum electronic devices working in the area of quantum computing. When two communities share the same goals, the universality of physics unavoidably leads to similar developments. However, the communication barrier is often high, and few physicists are able to overcome it. This school has contributed to bridge the existing gap between communities, for the benefit of the future actors in the field of quantum computing.
The book thus combines introductory chapters, providing the reader with a sufficiently wide theoretical framework in quantum information, quantum optics and quantum circuits physics, with more specialized presentations of recent theoretical and experimental advances in the field. This structure makes the book accessible to any graduatestudent having a good knowledge of basic quantum mechanics, and extremely useful to researchers.
-Covers quantum optics, solid state physics and NMR implementations
-Pedagogical approach combining introductory lectures and advanced chapters
-Written by leading experts in the field
-Accessible to all graduate students with a basic knowledge of quantum mechanics

The counter-intuitive aspects of quantum physics have been long illustrated by thought experiments, from Einstein's photon box to Schroedinger's cat. These experiments have now become real, with single particles - electrons, atoms, or photons - directly unveiling the strange features of the quantum. State superpositions, entanglement and complementarity define a novel quantum logic which can be harnessed for information processing, raising great hopes for applications. This book describes a class of such thought experiments made real. Juggling with atoms and photons confined in cavities, ions or cold atoms in traps, is here an incentive to shed a new light on the basic concepts of quantum physics. Measurement processes and decoherence at the quantum-classical boundary are highlighted. This volume, which combines theory and experiments, will be of interest to students in quantum physics, teachers seeking illustrations for their lectures and new problem sets, researchers in quantum optics and quantum information.