Master's Thesis from the year 2011 in the subject Physics - Quantum Physics, Shahjalal University of Science and Technology (Department of Physics), course: Nanostructure Physics, language: English, abstract: This book contains a comprehensive account of application of WKB method to pure Physics of nanostructures containing single or symmetric double barrier V(x) in their band model in presence of longitudinal magnetic field applied along x direction. It concentrates on effects on transmission coefficient of single and symmetric double barriers by three dimensional electron gas (3DEG). Analytical expressions for longitudinal magnetic field dependent transmission coefficient of single and symmetric double barrier of general shape are obtained first. These general expressions are then used to obtain analytical expressions of longitudinal magnetic field dependent transmission coefficient of single and symmetric double barriers of many different shapes we encounter in studying nanostructure Physics. This is followed by thorough numerical investigation to bring out effects of longitudinal magnetic field on transmission coefficient of all these barriers. Comparisons with standard results where available showed excellent agreements. Results of numerical investigation have been explained completely. The book makes well documented, with thorough calculation and discussion, pure Physics of semiconductor nanostructures.

Master's Thesis from the year 2011 in the subject Physics - Quantum Physics, grade: -, Shahjalal University of Science and Technology (Department of Physics), course: Nanostructure Physics, language: English, abstract: This book contains a comprehensive account of application of WKB method to pure Physics of nanostructures containing single or symmetric double barrier V(x) in their band model in presence of longitudinal magnetic field applied along x direction. It concentrates on effects on transmission coefficient of single and symmetric double barriers by three dimensional electron gas (3DEG). Analytical expressions for longitudinal magnetic field dependent transmission coefficient of single and symmetric double barrier of general shape are obtained first. These general expressions are then used to obtain analytical expressions of longitudinal magnetic field dependent transmission coefficient of single and symmetric double barriers of many different shapes we encounter in studying nanostructure Physics. This is followed by thorough numerical investigation to bring out effects of longitudinal magnetic field on transmission coefficient of all these barriers. Comparisons with standard results where available showed excellent agreements. Results of numerical investigation have been explained completely. The book makes well documented, with thorough calculation and discussion, pure Physics of semiconductor nanostructures.

The book deals with pure Nanostructure Physics of a Quantum Well (QW) of general shape adjacent to a tunnel barrier of general shape. On the other side of the QW, we have a barrier of semi-infinite thickness. Using WKB approximation method, the book presents thorough and complete analytical calculations leading to 2 transcendental equations obeyed by quasi-bound energy levels of the non-isolated QW. The 2 general equations have been applied to the cases when the tunnel barrier is rectangular, moderately biased rectangular, triangular and Schottky barrier. Thorough numerical investigations have been reported to bring out parametric variations of the energy levels. For some values of tunnel barrier height and width, the energy levels split into doublets. The book contains a thorough introduction to WKB method; the book also contains necessary background on Microelectronics and Nanostructure Physics to enable readers assimilate the book completely. The 1st 3 chapters are introductory while chapter 4 and 5 are exclusive and original contributions of the book.

Presenting in a coherent and accessible fashion current results in nanomagnetism, this book constitutes a comprehensive, rigorous and readable account, from first principles of the classical and quantum theories underlying the dynamics of magnetic nanoparticles subject to thermal fluctuations.Starting with the Larmor-like equation for a giant spin, both the stochastic (Langevin) equation of motion of the magnetization and the associated evolution (Fokker-Planck) equation for the distribution function of the magnetization orientations of ferromagnetic nanoparticles (classical spins) in a heat bath are developed along with their solution (using angular momentum theory) for arbitrary magnetocrystalline-Zeeman energy. Thus, observables such as the magnetization reversal time, relaxation functions, dynamic susceptibilities, etc. are calculated and compared with the predictions of classical escape rate theory including in the most general case spin-torque-transfer. Regarding quantum effects, which are based on the reduced spin density matrix evolution equation in Hilbert space as is described at length, they are comprehensively treated via the Wigner-Stratonovich formulation of the quantum mechanics of spins via their orientational quasi-probability distributions on a classically meaningful representation space. Here, as suggested by the relevant Weyl symbols, the latter is the configuration space of the polar angles. Hence, one is led, by mapping the reduced density matrix equation onto that space, to a master equation for the quasi-probability evolution akin to the Fokker-Planck equation which may be solved in a similar way. Thus, one may study in a classical-like manner the evolution of observables with spin number ranging from an elementary spin to molecular clusters to the classical limit, viz. a nanoparticle. The entire discussion hinges on the one-to-one correspondence between polarization operators in Hilbert space and the spherical harmonics allied to concepts of spin coherent states long familiar in quantum optics.Catering for the reader with only a passing knowledge of statistical and quantum mechanics, the book serves as an introductory text on a complicated subject where the literature is remarkably sparse.

The work was done by Polash Ranjan Dey as M.S. thesis in the Department of Physics, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh. The work was supervised by Dr. Sujaul Chowdhury, [email protected]. The work gives a thorough illustration of use of wave mechanics to semiconductor nanostructure in presence of magnetic field. The work covers complete analytical calculation and thorough numerical investigation with complete explanation of the results obtained.

The work provides a thorough illustration of use of WKB method to barrier transmission problem. On reading the book, the reader will be adept in using the method. Single and symmetric double barriers of general shape are treated first. Then single and symmetric double barriers of many different shapes we encounter in studying Nanostructure Physics are covered. Complete analytical calculation and results of extensive numerical investigation are reported along with comparison with standard results where available showing excellent agreement.

Nanostructure Physics and Fabrication contains the contributions of an interdisciplinary group of specialists in nanometer scale fabrication, physics of mesoscopic systems, electronic transport, and materials science brought together to discuss the current status of nanometer scale electronic structures. These articles provide the most current assessment of this active and growing area of interest. The introductory chapter provides comments and background material for those somewhat unfamiliar with this new area of research and serves as a condensed overview and summary of the contributions that follow. - Most current assessment of the field - Articles by experts in the field - Results presented here will impact the future of microelectronics

The book is an introduction to quantum field theory applied to condensed matter physics. The topics cover modern applications in electron systems and electronic properties of mesoscopic systems and nanosystems. The textbook is developed for a graduate or advanced undergraduate course with exercises which aim at giving students the ability to confront real problems.

This book fills a gap between many of the basic solid state physics and materials sciencebooks that are currently available. It is written for a mixed audience of electricalengineering and applied physics students who have some knowledge of elementaryundergraduate quantum mechanics and statistical mechanics. This book, based on asuccessful course taught at MIT, is divided pedagogically into three parts: (I) ElectronicStructure, (II) Transport Properties, and (III) Optical Properties. Each topic is explainedin the context of bulk materials and then extended to low-dimensional materials whereapplicable. Problem sets review the content of each chapter to help students to understandthe material described in each of the chapters more deeply and to prepare them to masterthe next chapters.