The subject of this book is a presentation of some aspects of modern theory of open quantum systems. It introduces several up-to- date topics, such as detecting quantum entanglement, modeling of quantum noise, quantum communication processes, and computational complexity in the analysis of quantum operations. Also discussed are light propagation in optically dressed media, as well as entropy and information measure for quantized electromagnetic fields media. This book is intended for researchers and students interested in the theory of open quantum systems, quantum information theory and quantum systems interacting with electromagnetic fields.

This book studies the fundamental aspects of many-body physics in quantum systems open to an external world. Recent remarkable developments in the observation and manipulation of quantum matter at the single-quantum level point to a new research area of open many-body systems, where interactions with an external observer and the environment play a major role. The first part of the book elucidates the influence of measurement backaction from an external observer, revealing new types of quantum critical phenomena and out-of-equilibrium dynamics beyond the conventional paradigm of closed systems. In turn, the second part develops a powerful theoretical approach to study the in- and out-of-equilibrium physics of an open quantum system strongly correlated with an external environment, where the entanglement between the system and the environment plays an essential role. The results obtained here offer essential theoretical results for understanding the many-body physics of quantum systems open to an external world, and can be applied to experimental systems in atomic, molecular and optical physics, quantum information science and condensed matter physics.

Recent research in the fields related to the quantum information theory (QIT) is becoming some of the most intriguing and promising investigations in contemporary physics. Many novel QIT concepts are discussed in the literature, and the broad range of new models of quantum optics and solid-state physics have been recently considered in the context of QIT. Theideas of symmetry are widely discussed in all physical sciences, becoming keystones of various concepts and considerations, leading to novel discoveries in physics. Thus, this Special Issue is devoted to the broad range of QIT topics that are related to the ideas of symmetry. It covers a broad range of ideas that can develop upon the basic research and applications in the field of quantum information, and in general, quantum theory.

This book highlights the applications of continuous-variable entangled state representations in the research areas of quantum optics via the integration method within an ordered product of operators (IWOP). As a way to develop the Dirac’s symbolic method, the IWOP method has made the integration of non-commutative operators possible by arranging non-commutable operators within an ordered product symbol. It not only deals with many existent quantum optics problems but also explores new research fields. The book also establishes a theoretical framework for solving important quantum optics subjects by taking full advantage of the entangled state representations. With original methods and detailed descriptions, the book is suitable for researchers, instructors, and students interested in quantum mechanics, quantum optics, and quantum information science.

This book is the proceedings of the 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology (ISQM—TOKYO'08) which aims to link the recent advances in technology with fundamental problems in quantum mechanics. It also discusses fundamental problems and issues in quantum physics and places a special emphasis on “Quantum Coherence and Decoherence”.The proceedings included a special lecture by Prof C N Yang, “Pseudopotential Method in Cold Atom Research”, and 75 refereed papers covering the wide range of quantum physics: cold atoms and molecules; spin-Hall effect and anomalous Hall effect; magnetic domain wall dynamics and spin-related phenomena; Dirac fermions in condensed matter; quantum dot systems; entanglement and quantum information processing, qubit manipulations; mechanical properties of confined geometry; precise measurements; novel properties of nano-systems; and fundamental problems in quantum physics.The book will not only serve as a good reference for experts on quantum coherence and decoherence, but also as an introduction for newcomers to this field.

This book is the proceedings of the 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology (ISQMOCoTOKYO''08) which aims to link the recent advances in technology with fundamental problems in quantum mechanics. It also discusses fundamental problems and issues in quantum physics and places a special emphasis on OC Quantum Coherence and DecoherenceOCO. The proceedings included a special lecture by Prof C N Yang, OC Pseudopotential Method in Cold Atom ResearchOCO, and 75 refereed papers covering the wide range of quantum physics: cold atoms and molecules; spin-Hall effect and anomalous Hall effect; magnetic domain wall dynamics and spin-related phenomena; Dirac fermions in condensed matter; quantum dot systems; entanglement and quantum information processing, qubit manipulations; mechanical properties of confined geometry; precise measurements; novel properties of nano-systems; and fundamental problems in quantum physics. The book will not only serve as a good reference for experts on quantum coherence and decoherence, but also as an introduction for newcomers to this field."

This volume aims to return to the starting point of the fields of infinite dimensional analysis and quantum probability, fields that are growing rapidly at present, and to seriously attempt mutual interaction between the two, with a view to enumerating and solving the many fundamental problems they entail. For such a purpose, we look for interdisciplinary bridges in mathematics including classical probability and to different branches of physics, in particular, research for new paradigms for information science on the basis of quantum theory.

The purpose of this proceedings volume is to return to the starting point of bio-informatics and quantum information, fields that are growing rapidly at present, and to seriously attempt mutual interaction between the two, with a view to enumerating and solving the many fundamental problems they entail. For such a purpose, we look for interdisciplinary bridges in mathematics, physics, information and life sciences, in particular, research for new paradigm for information science and life science on the basis of quantum theory.

Combining physics and philosophy, this is a uniquely interdisciplinary examination of quantum information science. Suitable as both a discussion of the conceptual and philosophical problems of this field and a comprehensive stand-alone introduction, this book will benefit both experienced and new researchers in quantum information and the philosophy of physics.

This thesis sheds new light on the fascinating properties of composite quantum systems. Quantum systems of different sizes, ranging from small bipartite systems to large many-body ensembles, can be studied with the help of modern quantum optical experiments. These experiments make it possible to observe a broad variety of striking features, including nonclassical correlations, complex dynamics and quantum phase transitions. By adopting the complementary perspectives of quantum information theory, quantum chemistry and many-body theory, the thesis develops new methods for the efficient characterization and description of interacting, composite quantum systems.