Quantum Transport Theory


Book Description

This book provides an introduction to transport theory, the kinetic equation approach and shows the utility of Feynman diagrams in non-equilibrium quantum statistical mechanics. It is helpful for a wider audience than students of condensed matter physics and physicists in general.




Theory of Quantum Transport at Nanoscale


Book Description

This book is an introduction to a rapidly developing field of modern theoretical physics – the theory of quantum transport at nanoscale. The theoretical methods considered in the book are in the basis of our understanding of charge, spin and heat transport in nanostructures and nanostructured materials and are widely used in nanoelectronics, molecular electronics, spin-dependent electronics (spintronics) and bio-electronics. The book is based on lectures for graduate and post-graduate students at the University of Regensburg and the Technische Universität Dresden (TU Dresden). The first part is devoted to the basic concepts of quantum transport: Landauer-Büttiker method and matrix Green function formalism for coherent transport, Tunneling (Transfer) Hamiltonian and master equation methods for tunneling, Coulomb blockade, vibrons and polarons. The results in this part are obtained as possible without sophisticated techniques, such as nonequilibrium Green functions, which are considered in detail in the second part. A general introduction into the nonequilibrium Green function theory is given. The approach based on the equation-of-motion technique, as well as more sophisticated one based on the Dyson-Keldysh diagrammatic technique are presented. The main attention is paid to the theoretical methods able to describe the nonequilibrium (at finite voltage) electron transport through interacting nanosystems, specifically the correlation effects due to electron-electron and electron-vibron interactions.




Quantum Transport


Book Description

Quantum transport is a diverse field, sometimes combining seemingly contradicting concepts - quantum and classical, conduction and insulating - within a single nanodevice. Quantum transport is an essential and challenging part of nanoscience, and understanding its concepts and methods is vital to the successful fabrication of devices at the nanoscale. This textbook is a comprehensive introduction to the rapidly developing field of quantum transport. The authors present the comprehensive theoretical background, and explore the groundbreaking experiments that laid the foundations of the field. Ideal for graduate students, each section contains control questions and exercises to check readers' understanding of the topics covered. Its broad scope and in-depth analysis of selected topics will appeal to researchers and professionals working in nanoscience.




Quantum Transport


Book Description

This book presents the conceptual framework underlying the atomistic theory of matter, emphasizing those aspects that relate to current flow. This includes some of the most advanced concepts of non-equilibrium quantum statistical mechanics. No prior acquaintance with quantum mechanics is assumed. Chapter 1 provides a description of quantum transport in elementary terms accessible to a beginner. The book then works its way from hydrogen to nanostructures, with extensive coverage of current flow. The final chapter summarizes the equations for quantum transport with illustrative examples showing how conductors evolve from the atomic to the ohmic regime as they get larger. Many numerical examples are used to provide concrete illustrations and the corresponding Matlab codes can be downloaded from the web. Videostreamed lectures, keyed to specific sections of the book, are also available through the web. This book is primarily aimed at senior and graduate students.




Scattering Matrix Approach to Non-stationary Quantum Transport


Book Description

The aim of this book is to introduce the basic elements of the scattering matrix approach to transport phenomena in dynamical quantum systems of non-interacting electrons. This approach permits a physically clear and transparent description of transport processes in dynamical mesoscopic systems, promising basic elements of solid-state devices for quantum information processing. One of the key effects, the quantum pump effect, is considered in detail. In addition, the theory for the recently implemented new dynamical source ? injecting electrons with time delay much larger than an electron coherence time ? is offered. This theory provides a simple description of quantum circuits with such a single-particle source and shows in an unambiguous way that the tunability inherent to the dynamical systems (in contrast to the stationary ones) leads to a number of unexpected but fundamental effects.




Nonequilibrium Quantum Transport Physics In Nanosystems: Foundation Of Computational Nonequilibrium Physics In Nanoscience And Nanotechnology


Book Description

This book presents the first comprehensive treatment of discrete phase-space quantum mechanics and the lattice Weyl-Wigner formulation of energy band dynamics, by the originator of these theoretical techniques. The author's quantum superfield theoretical formulation of nonequilibrium quantum physics is given in real time, without the awkward use of artificial time contour employed in previous formulations. These two main quantum theoretical techniques combine to yield general (including quasiparticle-pairing dynamics) and exact quantum transport equations in phase-space, appropriate for nanodevices. The derivation of transport formulas in mesoscopic physics from the general quantum transport equations is also treated. Pioneering nanodevices are discussed in the light of the quantum-transport physics equations, and an in-depth treatment of the physics of resonant tunneling devices is given. Operator Hilbert-space methods and quantum tomography are discussed. Discrete phase-space quantum mechanics on finite fields is treated for completeness and by virtue of its relevance to quantum computing. The phenomenological treatment of evolution superoperator and measurements is given to help clarify the general quantum transport theory. Quantum computing and information theory is covered to demonstrate the foundational aspects of discrete quantum dynamics, particularly in deriving a complete set of multiparticle entangled basis states.




Theory of Electron Transport in Semiconductors


Book Description

This book originated out of a desire to provide students with an instrument which might lead them from knowledge of elementary classical and quantum physics to moderntheoreticaltechniques for the analysisof electrontransport in semiconductors. The book is basically a textbook for students of physics, material science, and electronics. Rather than a monograph on detailed advanced research in a speci?c area, it intends to introduce the reader to the fascinating ?eld of electron dynamics in semiconductors, a ?eld that, through its applications to electronics, greatly contributed to the transformationof all our lives in the second half of the twentieth century, and continues to provide surprises and new challenges. The ?eld is so extensive that it has been necessary to leave aside many subjects, while others could be dealt with only in terms of their basic principles. The book is divided into ?ve major parts. Part I moves from a survey of the fundamentals of classical and quantum physics to a brief review of basic semiconductor physics. Its purpose is to establish a common platform of language and symbols, and to make the entire treatment, as far as pos- ble, self-contained. Parts II and III, respectively, develop transport theory in bulk semiconductors in semiclassical and quantum frames. Part IV is devoted to semiconductor structures, including devices and mesoscopic coherent s- tems. Finally, Part V develops the basic theoretical tools of transport theory within the modern nonequilibrium Green-function formulation, starting from an introduction to second-quantization formalism.




Quantum Transport in Nanostructures and Molecules


Book Description

This reference text presents a conceptual framework for understanding room-temperature electron and phonon transport through molecules and other quantum objects. The flow of electricity through molecules is explained at the boundary of physics and chemistry, providing an authoritative introduction to molecular electronics for physicists, and quantum transport for chemists. Professor Lambert provides a pedagogical account of the fundamental concepts needed to understand quantum transport and thermoelectricity in molecular-scale and nanoscale structures. The material provides researchers and advanced students with an understanding of how quantum transport relates to other areas of materials modelling, condensed matter and computational chemistry. After reading the book, the reader will be familiar with the basic concepts of molecular-orbital theory and scattering theory, which underpin current theories of quantum transport.




Quantum Kinetics in Transport and Optics of Semiconductors


Book Description

The state-of-the-art of quantum transport and quantum kinetics in semiconductors, plus the latest applications, are covered in this monograph. Since the publishing of the first edition in 1996, the nonequilibrium Green function technique has been applied to a large number of new research topics, and the revised edition introduces the reader to many of these areas. This book is both a reference work for researchers and a self-tutorial for graduate students.




Theory of Transport Properties of Semiconductor Nanostructures


Book Description

Recent advances in the fabrication of semiconductors have created almost un limited possibilities to design structures on a nanometre scale with extraordinary electronic and optoelectronic properties. The theoretical understanding of elec trical transport in such nanostructures is of utmost importance for future device applications. This represents a challenging issue of today's basic research since it requires advanced theoretical techniques to cope with the quantum limit of charge transport, ultrafast carrier dynamics and strongly nonlinear high-field ef fects. This book, which appears in the electronic materials series, presents an over view of the theoretical background and recent developments in the theory of electrical transport in semiconductor nanostructures. It contains 11 chapters which are written by experts in their fields. Starting with a tutorial introduction to the subject in Chapter 1, it proceeds to present different approaches to transport theory. The semiclassical Boltzmann transport equation is in the centre of the next three chapters. Hydrodynamic moment equations (Chapter 2), Monte Carlo techniques (Chapter 3) and the cellular au tomaton approach (Chapter 4) are introduced and illustrated with applications to nanometre structures and device simulation. A full quantum-transport theory covering the Kubo formalism and nonequilibrium Green's functions (Chapter 5) as well as the density matrix theory (Chapter 6) is then presented.