Submicron and nanoscale systems have risen on the research agenda. Exploiting the technological potential offered by these exotic materials requires a fundamental understanding of basic physical phenomena on the mesoscopic and nanoscopic scales. This book, written by leading experts in the field, covers such topics as the Kondo effect, electron transport, disorder and quantum coherence with electron-electron interaction, persistent current and thermoelectric phenomena, in quantum dots, quantum wires, carbon nanotubes and more.

The purpose of this collective book is to present a non-exhaustive survey of sp- related phenomena in semiconductors with a focus on recent research. In some sense it may be regarded as an updated version of theOpticalOrientation book, which was entirely devoted to spin physics in bulk semiconductors. During the 24 years that have elapsed, we have witnessed, on the one hand, an extraordinary development in the wonderful semiconductor physics in two dim- sions with the accompanying revolutionary applications. On the other hand, during the last maybe 15 years there was a strong revival in the interest in spin phen- ena, in particular in low-dimensional semiconductor structures. While in the 1970s and 1980s the entire world population of researchers in the ?eld never exceeded 20 persons, now it can be counted by the hundreds and the number of publications by the thousands. This explosive growth is stimulated, to a large extent, by the hopes that the electron and/or nuclear spins in a semiconductor will help to accomplish the dream of factorizing large numbers by quantum computing and eventually to develop a new spin-based electronics, or “spintronics”. Whether any of this will happen or not, still remains to be seen. Anyway, these ideas have resulted in a large body of interesting and exciting research, which is a good thing by itself. The ?eld of spin physics in semiconductors is extremely rich and interesting with many spectacular effects in optics and transport.

With the development of the scanning tunneling microscope, nanoscience became an important discipline. Single atoms could be manipulated in a controlled manner, and it became possible to change matter at its 'ultimate' level; it is the level on which the properties of matter emerge. This possibility enables to construct and to produce devices, materials, etc. with very small sizes and completely new properties. That opens up new perspectives for technology and is in particular relevant in connection with nano-engineering.Nanosystems are unimaginably small and very fast. No doubt, this is an important characteristic. But there is another feature, possibly more relevant, in connection with nanoscience and nanotechnology. The essential point here is that we work at the 'ultimate level'. This is the smallest level at which the properties of our world emerge, at which functional matter can exist. In particular, at this level biological individuality comes into existence. This situation can be expressed in absolute terms: This is not only the strongest material ever made, this is the strongest material it will ever be possible to make (D Ratner and M Ratner, Nanotechnology and Homeland Security). This is a very general statement. All aspects of matter are concerned here. Through the variation of the composition various forms of matter emerge with different items.Nanosystems are usually small, but they offer nevertheless the possibility to vary the structure of atomic (molecular) ensembles, creating a diversity of new material-specific properties. A large variety of experimental possibilities come into play and flexible theoretical tools are needed at the basic level. This is reflected in the different disciplines: In nanoscience and nanotechnology we have various directions: Materials science, functional nanomaterials, nanoparticles, food chemistry, medicine with brain research, quantum and molecular computing, bioinformatics, magnetic nanostructures, nano-optics, nano-electronics, etc.The properties of matter, which are involved within these nanodisciplines, are ultimate in character, i.e., their characteristic properties come into existence at this level. The book is organized in this respect.

With the development of the scanning tunneling microscope, nanoscience became an important discipline. Single atoms could be manipulated in a controlled manner, and it became possible to change matter at its 'ultimate' level; it is the level on which the properties of matter emerge. This possibility enables to construct and to produce devices, materials, etc. with very small sizes and completely new properties. That opens up new perspectives for technology and is in particular relevant in connection with nano-engineering.Nanosystems are unimaginably small and very fast. No doubt, this is an important characteristic. But there is another feature, possibly more relevant, in connection with nanoscience and nanotechnology. The essential point here is that we work at the 'ultimate level'. This is the smallest level at which the properties of our world emerge, at which functional matter can exist. In particular, at this level biological individuality comes into existence. This situation can be expressed in absolute terms: This is not only the strongest material ever made, this is the strongest material it will ever be possible to make (D Ratner and M Ratner, Nanotechnology and Homeland Security). This is a very general statement. All aspects of matter are concerned here. Through the variation of the composition various forms of matter emerge with different items.Nanosystems are usually small, but they offer nevertheless the possibility to vary the structure of atomic (molecular) ensembles, creating a diversity of new material-specific properties. A large variety of experimental possibilities come into play and flexible theoretical tools are needed at the basic level. This is reflected in the different disciplines: In nanoscience and nanotechnology we have various directions: Materials science, functional nanomaterials, nanoparticles, food chemistry, medicine with brain research, quantum and molecular computing, bioinformatics, magnetic nanostructures, nano-optics, nano-electronics, etc.The properties of matter, which are involved within these nanodisciplines, are ultimate in character, i.e., their characteristic properties come into existence at this level. The book is organized in this respect.

Group theoretical concepts elucidate fundamental physical phenomena, including excitation spectra of quantum systems and complex geometrical structures such as molecules and crystals. These concepts are extensively covered in numerous textbooks. The aim of the present monograph is to illuminate more subtle aspects featuring group theory for quantum mechanics, that is, the concept of dynamical symmetry. Dynamical symmetry groups complement the conventional groups: their elements induce transitions between states belonging to different representations of the symmetry group of the Hamiltonian. Dynamical symmetry appears as a hidden symmetry in the hydrogen atom and quantum rotator problem, but its main role is manifested in nano and meso systems. Such systems include atomic clusters, large molecules, quantum dots attached to metallic electrodes, etc. They are expected to be the building blocks of future quantum electronic devices and information transmitting algorithms. Elucidation of the electronic properties of such systems is greatly facilitated by applying concepts of dynamical group theory.

Approx.528 pagesApprox.528 pages