Quantum Dynamics of Submicron Structures


Book Description

Techniques for the preparation of condensed matter systems have advanced considerably in the last decade, principally due to the developments in microfabrication technologies. The widespread availability of millikelvin temperature facilities also led to the discovery of a large number of new quantum phenomena. Simultaneously, the quantum theory of small condensed matter systems has matured, allowing quantitative predictions. The effects discussed in Quantum Dynamics of Submicron Structures include typical quantum interference phenomena, such as the Aharonov-Bohm-like oscillations of the magnetoresistance of thin metallic cylinders and rings, transport through chaotic billiards, and such quantization effects as the integer and fractional quantum Hall effect and the quantization of the conductance of point contacts in integer multiples of the `conductance quantum'. Transport properties and tunnelling processes in various types of normal metal and superconductor tunnelling systems are treated. The statistical properties of the quantum states of electrons in spatially inhomogeneous systems, such as a random, inhomogeneous magnetic field, are investigated. Interacting systems, like the Luttinger liquid or electrons in a quantum dot, are also considered. Reviews are given of quantum blockade mechanisms for electrons that tunnel through small junctions, like the Coulomb blockade and spin blockade, the influence of dissipative coupling of charge carriers to an environment, and Andreev scattering. Coulomb interactions and quantization effects in transport through quantum dots and in double-well potentials, as well as quantum effects in the motion of vortices, as in the Aharonov-Casher effect, are discussed. The status of the theory of the metal-insulator and superconductor-insulator phase transitions in ordered and disordered granular systems are reviewed as examples in which such quantum effects are of great importance.




Quantum Transport in Semiconductor Submicron Structures


Book Description

The articles in this book have been selected from the lectures of a NATO Advanced Study Institute held at Bad Lauterberg (Germany) in August 1995. Internationally well-known researchers in the field of mesoscopic quantum physics provide insight into the fundamental physics underlying the mesoscopic transport phenomena in structured semiconductor inversion layers. In addition, some of the most recent achievements are reported in contributed papers. The aim of the volume is not to give an overview over the field. Instead, emphasis is on interaction and correlation phenomena that turn out to be of increasing importance for the understanding of the phenomena in the quantum Hall regime, and in the transport through quantum dots. The present status of the quantum Hall experiments and theory is reviewed. As a "key example" for non-Fermi liquid behavior the Luttinger liquid is introduced, including some of the most recent developments. It is not only of importance for the fractional quantum Hall effect, but also for the understanding of transport in quantum wires. Furthermore, the chaotic and the correlation aspects of the transport in quantum dot systems are described. The status of the experimental work in the area of persistent currents in semiconductor systems is outlined. The construction of one of the first single-electron transistors is reported. The theoretical approach to mesoscopic transport, presently a most active area, is treated, and some aspects of time-dependent transport phenomena are also discussed.




Chemical, Structural and Electronic Analysis of Heterogeneous Surfaces on Nanometer Scale


Book Description

An assessment of the recent achievements and relative strengths of two developing techniques for characterising surfaces at the nanometer scale: (i) local probe methods, including scanning tunnelling microscopy and its derivatives; and (ii) nanoscale photoemission and absorption spectroscopy for chemical analysis. The keynote lectures were delivered by some of the world's best scientists in the field and some of the topics covered include: (1) The possible application of STM in atomically resolved chemical analysis. (2) The principles of scanning force/friction and scanning near-field optical microscopes. (3) The scanning photoemission electron microscopes built at ELETTRA and SRRC, with a description of synchrotron radiation microscopy. (4) Recent progress in the development of spatially-resolved photoelectron microscopy, especially the use of zone plate photon optics. (5) The present status of non-scanning photoemission microscopy with slow electrons. (6) the BESSY 2 project for a non-scanning photoelectron microscope with electron optics. (7) Spatially-resolved in situ reaction studies of chemical waves and oscillatory phenomena with the UV photoemission microscope.




Mesoscopic Electron Transport


Book Description

Ongoing developments in nanofabrication technology and the availability of novel materials have led to the emergence and evolution of new topics for mesoscopic research, including scanning-tunnelling microscopic studies of few-atom metallic clusters, discrete energy level spectroscopy, the prediction of Kondo-type physics in the transport properties of quantum dots, time dependent effects, and the properties of interacting systems, e.g. of Luttinger liquids. The overall understanding of each of these areas is still incomplete; nevertheless, with the foundations laid by studies in the more traditional systems there is no doubt that these new areas will advance mesoscopic electron transport to a new phenomenological level, both experimentally and theoretically. Mesoscopic Electron Transport highlights selected areas in the field, provides a comprehensive review of such systems, and also serves as an introduction to the new and developing areas of mesoscopic electron transport.




Quantum Tunneling of Magnetization — QTM ’94


Book Description

The first NATO Advanced Workshop on Quantum Tunneling of Magnetization (QTM) was organized and co-directed by Bernard Barbara, Leon Gunther, Nicolas Garcia, and Anthony Leggett and was held from June, 27 through July 1, 1994 in Grenoble and Chichilianne, France. These Proceedings include twenty-nine articles that represent the contributions of the participants in the Workshop. Quantum Tunneling of Magnetization is not only interesting for purely academic reasons. It was pointed out in the review article by L. Gunther in the December, 1990 issue of Physics World, that QTM may be destined to play a significant role within the next two decades in limiting the density of information storage in magnetic systems. Recent advances have indicated that this limitation may well be reached even earlier than first predicted. Furthermore, the number of people who have entered the field of study of QTM during these past few years has increased many fi)ld. The time was therefore opportune to hold a Workshop to bring together for the first time the leading researchers of QTM, both theoretical and experimental, so as to discuss the current status of the field. The most controversial issue at the time of the Workshop was how to establish r.eliable criteria for determining whether experimental results do indeed reveal manifestations of QTM. We believe that much progress was made at the Workshop on this issue.




Frontiers in Nanoscale Science of Micron/Submicron Devices


Book Description

Nanoscale Science, whose birth and further growth and development has been driven by the needs of the microelectronics industry on one hand, and by the sheer human curiosity on the other hand, has given researchers an unprecedented capability to design and construct devices whose function ality is based on quantum and mesoscopic effects. A necessary step in this process has been the development of reliable fabrication techniques in the nanometer scale: two-dimensional systems, quantum wires and dots, and Coulomb blockade structures with almost ideal properties can nowadays be fabricated, and subjected to experimental studies. How does one fabricate micro/nanostructures of low dimensionality? How does one perform a nanoscale characterization of these structures? What are the fundamental properties typical to the structures? Which new physical processes in nanostructures need to be understood? What new physical processes may allow us to create new nanostructures? An improved understanding of these topics is necessary for creation of new concepts for future electronic and optoelectronic devices and for characterizing device structures based on those concepts.




Quantum Computation and Quantum Information Theory


Book Description

Quantum information theory has revolutionised our view on the true nature of information and has led to such intriguing topics as teleportation and quantum computation. The field - by its very nature strongly interdisciplinary, with deep roots in the foundations both of quantum mechanics and of information theory and computer science - has become a major subject for scientists working in fields as diverse as quantum optics, superconductivity or information theory, all the way to computer engineers.







Quantum Noise in Mesoscopic Physics


Book Description

This book is written to conclude the NATO Advanced Research Workshop "Quantum Noise in Mesoscopic Physics" held in Delft, the Netherlands, on June 2-4, 2002. The workshop was co-directed by M. Reznikov of Israel Institute of Technology, and me. The members of the organizing committee were Yaroslav Blanter (Delft), Chirstopher Glattli (Saclay and ENS Paris) and R. Schoelkopf (Yale). The workshop was very successful, and we hope that the reader will be satisfied with the scientific level of the present book. Before addressing scientific issues I find it suitable to address several non-scientific ones. The workshop was attended by researchers from many countries. Most of them perform their activities in academic institutions, where one usually finds the necessary isolation from the problems and sores of the modem world. However, there was a large group of participants for which such isolation was far from perfect. War, hatred, and violence rage just several miles away of their campuses and laboratories, poisoning everyday life in the land of Israel.




Microcavities and Photonic Bandgaps: Physics and Applications


Book Description

The control of optical modes in microcavities or in photonic bandgap (PBG) materials is coming of age! Although these ideas could have been developed some time ago, it is only recently that they have emerged, due to advances in both atomic physics and in fabrication techniques, be it on the high-quality dielectric mirrors required for high-finesse Fabry Perot resonators or in semiconductor multilayer deposition methods. Initially the principles of quantum electro-dynamics (QED) were demonstrated in elegant atomic physics experiments. Now solid-state implementations are being investigated, with several subtle differences from the atomic case such as those due to their continuum of electronic states or the near Boson nature of their elementary excitations, the exciton. Research into quantum optics brings us ever newer concepts with potential to improve system performance such as photon squeezing, quantum cryptography, reversible taps, photonic de Broglie waves and quantum computers. The possibility of implementing these ideas with solid-state systems gives us hope that some could indeed find their way to the market, demonstrating the continuing importance of basic research for applications, be it in a somewhat more focused way than in earlier times for funding.