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.

During the last few years, considerable interest has been focused on the phase that waves accumulate when the equations governing the waves vary slowly. The recent flurry of activity was set off by a paper by Michael Berry, where it was found that the adiabatic evolution of energy eigenfunctions in quantum mechanics contains a phase of geometric origin (now known as ‘Berry's phase’) in addition to the usual dynamical phase derived from Schrödinger's equation. This observation, though basically elementary, seems to be quite profound. Phases with similar mathematical origins have been identified and found to be important in a startling variety of physical contexts, ranging from nuclear magnetic resonance and low-Reynolds number hydrodynamics to quantum field theory. This volume is a collection of original papers and reprints, with commentary, on the subject. Contents:Introduction and OverviewAnticipationsFoundationsSome Applications and TestsFractional StatisticsQuantized Hall EffectWess-Zumino Terms and AnomaliesClassical SystemsAsymptotics Readership: Mathematical, high energy and condensed matter physicists.

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. Contents:Phase in Classical and Nonlinear OpticsPhase-Space Description of Light FieldPhase in Quantum OpticsPhase-Shift Measurements and Phase Dependence Readership: Researchers in applied physics, general physics, optics and laser physics. keywords:Interference of Light;Quasidistributions;Operator Orderings;Geometric Phase, Infamous Phase Operator;Phase Variability “We can be confident that any book with J Peřina among its authors will be a valuable contribution to coherence studies and Phase in Optics more than confirm … Certainly there has been much subsequent research on the subjects of this book but as an authoritative assessment of an important research area it has not lost its relevance.” Ultramicroscopy

Wigner's quasi-probability distribution function in phase space is a special (Weyl) representation of the density matrix. It has been useful in describing quantum transport in quantum optics; nuclear physics; decoherence, quantum computing, and quantum chaos. It is also important in signal processing and the mathematics of algebraic deformation. A remarkable aspect of its internal logic, pioneered by Groenewold and Moyal, has only emerged in the last quarter-century: it furnishes a third, alternative, formulation of quantum mechanics, independent of the conventional Hilbert space, or path integral formulations.In this logically complete and self-standing formulation, one need not choose sides ? coordinate or momentum space. It works in full phase space, accommodating the uncertainty principle, and it offers unique insights into the classical limit of quantum theory. This invaluable book is a collection of the seminal papers on the formulation, with an introductory overview which provides a trail map for those papers; an extensive bibliography; and simple illustrations, suitable for applications to a broad range of physics problems. It can provide supplementary material for a beginning graduate course in quantum mechanics.

Suitable for advanced undergraduates and graduate students, this compact treatment examines linear space, functionals, and operators; diagonalizing operators; operator algebras; and equations of motion. 1969 edition.

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).