This book provides the theoretical basis and the relevant experimental knowledge underlying our present understanding of the electrical and optical properties of semiconductor heterostructures. Although such structures have been known since the 1940s, it was only in the 1980s that they moved to the forefront of research, largely due to technological developments that made it possible to grow several ultrathin layers of different materials _ down to a few atoms in thickness _ on top of a silicon or other substrates. The resulting structures have remarkable properties not shared by bulk materials. One can, for example, confine the motions of electrons to a single layer, making it possible to investigate effectively two-dimensional systems. One can also build materials with large-scale periodicities by alternating layers of different compositions, thereby modulating the optical and electronic properties of the resulting structure. The text begins with a description of the electronic properties of various types of heterostructures, including discussions of complex band-structure effects, localized states, tunneling phenomena, and excitonic states. The focus of most of the remainder of the book is on optical properties, including intraband absorption, luminescence and recombination, Raman scattering, subband optical transitions, nonlinear effects, and ultrafast optical phenomena. The concluding chapter presents an overview of some of the applications that make use of the physics discussed. Appendices provide ackground information on band structure theoy, kinetic theory, electromagnetic modes, and Coulomb effects. Intended for graduate students, physicists, and engineers beginning research onsemiconductor heterostructures or interested in their

The theoretical basis and the relevant experimental knowledge underlying our present understanding of the electrical and optical properties of semiconductor heterostructures. Although such structures have been known since the 1940s, it was only in the 1980s that they moved to the forefront of research. The resulting structures have remarkable properties not shared by bulk materials. The text begins with a description of the electronic properties of various types of heterostructures, including discussions of complex band-structure effects, localised states, tunnelling phenomena, and excitonic states. The focus of the remainder of the book is on optical properties, including intraband absorption, luminescence and recombination, Raman scattering, subband optical transitions, nonlinear effects, and ultrafast optical phenomena. The concluding chapter presents an overview of some of the applications that make use of the physics discussed. Appendices provide background information on band structure theory, kinetic theory, electromagnetic modes, and Coulomb effects.

Theological conversations about violence have typically framed the discussion in terms of victim and perpetrator. Such work, while important, only addresses part of the problem. Comprehensive theological and pastoral responses to violence must also address the role of collective passivity in the face of human denigration. Given the pervasiveness of inaction-whether in the form of denial, willful ignorance, or silent complicity-a theological reflection on violence that holds bystanders accountable, especially those who occupy social sites of privilege, is long overdue. In Beyond Apathy, Elisabeth T. Vasko utilizes resources within the Christian tradition to examine the theological significance of bystander participation in patterns of violence and violation within contemporary Western culture, giving particular attention to the social issues of bullying, white racism, and sexual violence. In doing so, she constructs a theology of redeeming grace for bystanders to violence that foregrounds the significance of social action in bringing about God's basileia.

This lecture-style monograph is addressed to several categories of readers. First, it will be useful for graduate students studying theory. Second, the topics covered should be interesting for postgraduate students of various specializations. Third, the researchers who want to understand the background of modern theoretical issues in more detail can find a number of useful results here. The phenomena covered involve kinetics of electron, phonon, and photon systems in solids. The dynamical properties and interactions of electrons, phonons, and photons are briefly described in Chapter 1. Further, in Chapters 2-8, the authors present the main theoretical methods: linear response theory, various kinetic equations for the quasiparticles under consideration, and diagram technique. The presentation of the key approaches is always accompanied by solutions of concrete problems to illustrate ways to apply the theory. The remaining chapters are devoted to various manifestations of quantum transport in solids. The choice of particular topics is determined by their scientific importance and methodological value.The 267 supplementary problems presented in the ends of chapters are offered to guide the reader in self-study. Focusing attention on the methodological aspects and discussing a great diversity of kinetic phenomena, in keeping with the guiding principle a method is more important than a result, the authors minimize both detailed discussion of physical mechanisms of the phenomena and the comparison of theoretical results to experimental data.