Physics

The book opens with a chapter on the classical theory of multipoles in electromagnetism, in which static and dynamic multipole expansions of various physical quantities are derived, including of the Maxwell fields D and H. Chapter 2 presents a semi-classical account of multipole theory, in which the Barron-Gray gauge is used to derive multipole polarizabilities describing the induction of molecular moments by a harmonic plane wave. Aspects of symmetry are treated in Chapter 3 — space-time behaviour of tensors and physical properties of molecules and crystals. In Chapter 4, D(E,B) and H(E,B) are obtained for linear anisotropic media, yielding expressions for the material constants which are required to satisfy origin independence, the Post constraint, and certain symmetries but fail the first two. Despite these difficulties, the standard theory is used in Chapter 5 to derive a wave propagation equation; this is applied to explain various physical effects in transmission, two of which are also described in a scattering theory. Chapter 6 deals with the reflection of electromagnetic waves from an anisotropic medium. The reflected intensities violate origin independence, showing again the unphysical nature of existing multipole theory. In Chapter 7, the fields are transformed while leaving Maxwell's equations unchanged, from which new material constants are derived in Chapter 8 that meet the three requirements in Chapter 4. Chapter 9 applies the transformed expressions to transmission and reflection phenomena, confirming the results of Chapter 5, while yielding reflected intensities that satisfy space and time invariances.

The theory of atomic structure proposed by the young Danish physicist Niels Bohr in 1913 marked the true beginning of modern atomic and quantum physics. This is the first book that focuses in detail on the origin and development of this remarkable theory. It offers a comprehensive account of Bohr’s ideas and the way they were modified by other physicists. By following the development and applications of the theory, it brings new insight into Bohr’s peculiar way of thinking; what Einstein once called his ‘musicality’ and ‘unique instinct and tact’. Contrary to most other accounts of the Bohr atom, the book presents it in a broader perspective, which includes the reception among other scientists, popular expositions of the theory, and the objections raised against it by scientists of a more conservative inclination. Moreover, it discusses the theory as Bohr originally conceived it, namely, as an ambitious attempt to understand the structure of atoms as well as molecules: the chemical aspects of the theory are given much attention. The book covers the successes as well as the failures of Bohr’s theory, arguing that the latter were no less important in the process that led Bohr to abandon the original model and Heisenberg to propose a new ‘quantum mechanics’. By discussing the theory in its entirety—following it from its birth in 1913, through its adolescence round 1918, to its decline in 1924—it becomes possible to understand its development and use it as an example of the dynamics of scientific theories.

This book is composed of two parts: progresses in photographic science (Part I) and application of photographic science to new areas (Part II). Part I describes the accumulated knowledge of photographic science including its recent progresses. Descriptions are made on the structure, formation, and physical properties of silver halide (AgX) nanoparticles and grains, the formation and performance of Ag clusters and nanoparticles on AgX grains, and dye sensitization with J-aggregated dye layers on AgX grains. Part II describes the application of the above-stated knowledge to new areas now developing for the future. They include digital photography with CCD and CMOS as sensors, new nuclear-truck emulsions for detection of unknown nuclear particles, silver nanoparticles with their surface plasmon resonance available for various purposes, dye-sensitized solar cells with Ru dyes on the layers of sintered nanoparticles of TiO2, and organic semiconductors in terms of light absorption and aggregation of dyes, electronic structures, behaviors of excitons, creation and transport of electronic charge carriers, and production of their devices in relation to colour films with J-aggregated dye layers on AgX grains. Leaving the accumulating knowledge on photographic science in record, this book provides these new areas with unique knowledge and ideas arising from their synergetic interaction with photographic science and technology that have been accumulating on the basis of nanoparticles, J-aggregates, and dye sensitization.

Using a selection of key experiments performed over the past thirty years or so, this book presents a discussion of the strikingly counter-intuitive phenomena of the quantum world that defy explanation in terms of everyday ‘common sense’ reasoning, and it provides the corresponding quantum mechanical explanations with a very elementary use of associated formalism. Most, but certainly not all, of the experiments described are optical experiments involving a very small number of photons (particles of light). The book begins with experiments on the wave-particle duality of electrons, proceeds to experiments on the particle nature of light and single photon interference, delayed choice experiments, and interaction-free detection; and then goes on to experiments involving the interference of two photons, quantum entanglement and Bell's Theorem, quantum teleportation, large-scale quantum effects, and the divide between the classical and quantum worlds, addressing the question as to whether or not there is such a divide.

This book is devoted to the physics and technology of diode lasers based on self-organized quantum dots (QD). It addresses the fundamental and technology aspects of QD edge-emitting and vertical-cavity surface-emitting lasers, reviewing their current status and future prospects. The theoretically predicted advantages of an ideal QD array for laser applications are discussed and the basic principles of QD formation using self-organization phenomena are reviewed. Structural and optical properties of self-organized QDs are considered with a number of examples in different material systems. The book includes recent achievements in controlling the QD properties such as the effect of vertical stacking, changing the matrix bandgap and the surface density of QDs. The book is also focused on the use of self-organized quantum dots in laser structures, fabrication and characterization of edge- and surface-emitting diode lasers, their properties and optimization. Special attention is paid to the relationship between structural and electronic properties of QDs and laser characteristics. The threshold and power characteristics of the state-of-the-art QD lasers are also demonstrated. Issues related to the long-wavelength (1.3-um) lasers on a GaAs substrate are also addressed and recent results on InGaAsN-based diode lasers presented for the purpose of comparison.

Quantum optics is the field of physics describing the interaction of individual photons with matter, but in recent years it has expanded beyond pure physics to become an important driving force for technological innovation. This book starts with an elementary description of the underlying physics and then builds up a more advanced treatment. The theory begins with the quantum description of the simple harmonic oscillator, and is subsequently extended to provide the tools required to discuss coherent states, the interaction of light with atoms, entangled states, quantum noise and dissipation, linear optical amplifiers, and the fundamental issues associated with Bell's theorem. There is an equally strong emphasis on experimental methods. A quantum description of lenses, mirrors, beam splitters, Y-junctions, circulators, and stops is applied to a collection of important experiments in linear optics. A description of the most important methods of primary photon detection is followed by an explanation of heterodyne and homodyne techniques. Spontaneous down conversion and quantum tomography are discussed, together with important experimental applications. These experimental and theoretical considerations come together in a chapter briefly discussing quantum noise and its suppression in telecommunications; the limitations and possibilities for quantum cloning; the principles and techniques of quantum cryptography; and the physical basis for quantum computing.

This book collects lecture courses and seminars given at the Les Houches Summer School 2010 on ‘Quantum Theory: From Small to Large Scales’. Fundamental quantum phenomena appear on all scales, from microscopic to macroscopic. Some of the pertinent questions include the onset of decoherence, the dynamics of collective modes, the influence of external randomness, and the emergence of dissipative behaviour. Our understanding of such phenomena has been advanced by the study of model systems and by the derivation and analysis of effective dynamics for large systems and over long times. In this field, research in mathematical physics has regularly contributed results that were recognized as essential in the physics community. During the last few years, the key questions have been sharpened and progress on answering them has been particularly strong. This book reviews the state-of-the-art developments in this field and provides the necessary background for future studies.

The theory of intermolecular forces has advanced very greatly in the last few decades. Simple empirical models are no longer adequate to account for the detailed and accurate experimental measurements that are now available, or to predict properties such as the structures of molecular crystals reliably. At the same time computational methods for calculating intermolecular forces have improved enormously, so that it is possible to construct much more accurate intermolecular potential energy functions for much larger systems than was possible twenty years ago. The Theory of Intermolecular Forces describes these advances. It sets out the mathematical techniques that are needed to describe molecular properties and the ways that they contribute to the interactions between molecules. There is a detailed account of the use of multipole moments to describe electrostatic and related interactions, and both Cartesian and spherical tensor methods are described. Perturbation theories of intermolecular interactions, in particular the widely-used SAPT and SAPT-DFT methods, are discussed in detail. The many analytic models of intermolecular potentials are described and discussed, and the methods used to predict experimental properties from them are described.

Semiconductor optoelectronic devices are at the heart of all information generation and processing systems and are likely to be essential components of future optical computers. With more emphasis on optoelectronics and photonics in graduate programmes in physics and engineering, there is a need for a text providing a basic understanding of the important physical phenomena involved. Such a training is necessary for the design, optimization, and search for new materials, devices, and application areas. This book provides a simple quantum mechanical theory of important optical processes, i.e. band-to-band, intersubband, and excitonic absorption and recombination in bulk, quantum wells, wires, dots, superlattices, and strained layers including electro-optic effects. The classical theory of absorption, quantization of radiation, and band picture based on k p perturbation has been included to provide the necessary background. Prerequisites for the book are a knowledge of quantum mechanics and solid state theory. Problems have been set at the end of each chapter, some of which may guide the reader to study processes not covered in the book. The application areas of the phenomena are also indicated.

This book covers all aspects of the study of ground state electron density in condensed matter through Compton scattering of hard x-rays or gamma rays, i.e., photons with energies between 20 and 500 keV. This inelastic scattering process yields information about the momentum distribution of the electrons: it is complementary to x-ray diffraction studies of the position space electron density. After a brief historical introduction, the scattering cross-section is fully elaborated and the approximations within which the experiments can be interpreted are spelled out. All the experimental methods associated with the study of the electron’s momentum density distribution are described and the interpretative techniques are detailed, including the two methods of reconstructing the three-dimensional distribution from the measurement sets. Particular emphasis is placed on the use of synchrotron radiation as the radiation source, especially the use of circularly polarized synchrotron radiation to study the spin-dependent distribution in ferro-magnets. The book concludes with a comparison between Compton scattering methods and a number of allied techniques.