Describing the phase of an electromagnetic field mode or harmonic oscillator has been an obstacle since the early days of modern quantum theory. The quantum phase operator was even more problematic with the invention of the maser and laser in the 1950s and 1960s. This problem was not solved until the Pegg-Barnett formalism was developed in the 1980

Describing the phase of an electromagnetic field mode or harmonic oscillator has been an obstacle since the early days of modern quantum theory. The quantum phase operator was even more problematic with the invention of the maser and laser in the 1950s and 1960s. This problem was not solved until the Pegg-Barnett formalism was developed in the 1980s. Edited by one of the scientists who created this key solution, The Quantum Phase Operator: A Review charts the development of phase and angle operators from their first appearance to modern theory. Bringing together vital works that have been published on the subject, the book presents the ideas that led to the current theory of the phase operator and provides a complete picture of the progress that has followed since then. With introductions by the editors to put the papers in context and unify the content of the book, each section focuses on a different aspect of phase operators. The editors also chronologically organize the papers within the sections to highlight how scientific thought has evolved, if at all, over time. A collection of important relevant material that is scattered throughout the literature, this volume chronicles the history of the various facets of the quantum phase operator, promoting a solid foundation in quantum theory.

Symposium on the Foundations of Modern Physics 1993 is the fourth in a series of conferences held in Joensuu, Finland, in the years 1985, 1987 and 1990 and is devoted to offering discussions on foundational problems of quantum mechanics and other fundamental physical theories, taking into account new experimental developments. The surveying of the progress with respect to fundamental questions of the quantum theory of measurement forms the guiding line of thought of the present Symposium, the main themes discussed being: the interrelation of quantum measurement and irreversibility; the physics of information (concerned with questions of information processing and quantum noise); quantum interference and mesoscopic quantum effects (searching for the micro-macro borderline); and the quantum-classical relationship (the need for classical pointer and their realisation).

This book is devoted to the classical and quantum phases in wave and particle optics from the viewpoint of both theory and applications. Wave and beam light optics are reviewed in considerable detail, featuring optical imaging and holography in linear optics and phase conjugation methods in nonlinear optics. Photon optics is embodied here as quantum optics with the modes treated as quantum harmonic oscillators. The importance of the Wigner function for the phase space description in the context of canonical quantization is respected and the method of quasidistributions related to operator orderings in the second-quantized theory is exposed. The history of the quantum phase problem, characterized by renewed interest in the solution to the problem, is included and brought up to date. Approaches based on exponential phase operators, discrete phase states, the enlargement of the Hilbert space of the harmonic oscillator leading to the phase representations and distributions, together with solutions motivated by the quasidistributions, are introduced. The operational approach to the quantum phase is contrasted with the previous formalisms. The results of the study of the coherent states and the ordinary squeezed states from the viewpoint of the quantum phase and those of the analysis of the quantum statistics of phase-related special states of the light field are provided. The quantum phase is also treated with respect to quantum interferometry, particle interferometry, nonlinear optical processes, and quantum nondemolition measurements.The book will prove indispensable to research workers in general optics, quantum optics and electronics, optoelectronics, and nonlinear optics, as well as to students of physics, optics, optoelectronics, photonics, and optical engineering.

This long-awaited second edition provides an accessible but comprehensive introduction to the important field of quantum optics.

This book offers a modern way of dealing with the problems of equilibrium states of Bose systems. Starting with the variation principle of statistical mechanics and the energy-entropy balance principle as equilibrium criteria, results for general boson systems and models are explicitly derived using simple functional analytic calculus. Bridging the gap between general theoretical physics and the phenomenological research in the field of Bose systems, this book provides an insight into the fascinating quantum world of bosons. Key topics include the occurrence of BEC and its intimate structural relation with the phenomena of spontaneous symmetry breaking and off-diagonal long range order; the condensate equation; the issue concerning the choice of boundary conditions; solvable versus non-solvable boson models; the set of quasi-free boson states; the role of dissipative perturbations; and the surprising but general relation between general quantum fluctuations and boson systems. Only some knowledge of quantum mechanics and undergraduate algebra and analysis is assumed. This textbook brings students and researchers smoothly from general concepts to vivid applications.

The International Workshop on Quantum Communications and Measurement was held at the University of Nottingham from July 10-16, 1994. It followed the successful meeting on Quantum Aspects of Optical Communications in Paris in November 1990. This time the conference was devoted to mathematical, physical and engineering aspects of quantum noise, signal processing and quantum informa tion in open systems, quantum channels, and optical communications. It brought research workers in the experimental and engineering aspects of quantum optics and communication systems into contact with theoreticians working in quantum probability and measurement theory. The workshop was attended by more than 130 participants from 22 different countries. The largest groups [after the UK (31)] were from Japan (19) and from Russia (14). The subjects discussed included the mathematical foundations of quantum communication systems, experiments and devices, the problem of collapse and continuous measurement, quantum input and output processes, causality and nondemolition observation, squeezed states, quan tum jumps, state diffusion and spontaneous localization, filtering and control in quantum systems, and new quantum optical phenomena and effects, including non classical light. These new mathematical and physical ideas were stimulated by recent advances in generation and detection of light with low quantum noise and the development of techniques for trapping a single atom over an extended period of time, making it possible to observe individual quantum phenomena at the macroscopic level.

Volume XXXV contains six review articles.The first article is a discussion on transverse light patterns in non-linear media, lasers and wide aperture interferometers. The next article deals with the detection and spectroscopic studies of single molecules in transparent solids at low temperature. The isolated spectral line of a single molecule makes it possible to perform basic quantum measurements, and allows probing in unprecedented detail of the surrounding solid matrix. The article also includes some suggestions for future research in this field.The next article reviews interferometric techniques for retrieving multispectral images with a large number of spectral channels. Special attention is paid to the theory of interferometric multispectral imaging which unifies the theories of coherence based image retrieval and spectrum recovery. Various techniques are compared, especially in terms of signal-to-noise-ratio.

This book establishes the fundamental connections between the physics of quantum phase transitions and the technological promise of quantum information.

This book analyzes in considerable generality the quantization-dequantization integral transform scheme of Weyl and Wigner, and considers several phase operator theories. It features: a thorough treatment of quantization in polar coordinates; dequantization by a new method of "motes"; a discussion of Moyal algebras; modifications of the transform method to accommodate operator orderings; a rigorous discussion of the Dieke laser model for one mode, fully quantum, in the thermodynamic limit; analysis of quantum phase theories based on the Toeplitz operator, the coherent state operator, the quantized phase space angle, and a sequence of finite rank operators.