Download or read book Modeling A C Electronic Transport Through a Two Dimensional Quantum Point Contact written by and published by . This book was released on 1998 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A c Transport and Collective Excitation in a Quantum Point Contact written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors calculate the a.c.-admittance of a two dimensional quantum point contact (QPC) using a Boltzmann-like kinetic equation derived for the partial Wigner distribution function. An integral equation for a potential inside a QPC is solved numerically. The dependence of the admittance on the frequency of the a.c. field is found in a wide frequency range [omega] [approx] 0--50 GHz. The contribution to the imaginary part of the admittance due to the quantum capacitance and inductance is numerically calculated. It is shown that the crossover from localized parameters--quantum capacitance and inductance--to distributed behavior takes place at [omega] [approximately] 10 GHz. A transition from 2D plasmons to quasi-1D plasmons is analyzed as a function of two dimensionless parameters: k[sub x]d[sub 0] (where k[sub x] is the longitudinal wave vector, and d[sub 0] is the width of the QPC), and the number of open electron channels, N.
Download or read book Conceptual Foundations of Materials written by and published by Elsevier. This book was released on 2006-09-20 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this Volume "Conceptual Foundations of Materials: A standard model for ground- and excited-state properties" is to present the fundamentals of electronic structure theory that are central to the understanding and prediction of materials phenomena and properties. The emphasis is on foundations and concepts. The Sections are designed to offer a broad and comprehensive perspective of the field. They cover the basic aspects of modern electronic structure approaches and highlight their applications to the structural (ground state, vibrational, dynamic and thermodynamic, etc.) and electronic (spectroscopic, dielectric, magnetic, transport, etc.) properties of real materials including solids, clusters, liquids, and nanostructure materials. This framework also forms a basis for studies of emergent properties arising from low-energy electron correlations and interactions such as the quantum Hall effects, superconductivity, and other cooperative phenomena. Although some of the basics and models for solids were developed in the early part of the last century by figures such as Bloch, Pauli, Fermi, and Slater, the field of electronic structure theory went through a phenomenal growth during the past two decades, leading to new concepts, understandings, and predictive capabilities for determining the ground- and excited-state properties of real, complex materials from first principles. For example, theory can now be used to predict the existence and properties of materials not previously realized in nature or in the laboratory. Computer experiments can be performed to examine the behavior of individual atoms in a particular process, to analyze the importance of different mechanisms, or just to see what happen if one varies the interactions and parameters in the simulation. Also, with ab initio calculations, one can determine from first principles important interaction parameters which are needed in model studies of complex processes or highly correlated systems. Each time a new material or a novel form of a material is discovered, electronic structure theory inevitably plays a fundamental role in unraveling its properties. Provides the foundations of the field of condensed matter physics An excellent supplementary text for classes on condensed matter physics/solid state physics Volume covers current work at the forefront Presentations are accessible to nonspecialists, with focus on underlying fundamentals
Download or read book Electronic Transport in Two dimensional Systems in the Quantum Hall Regime written by Vinicio Tarquini and published by . This book was released on 2016 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Moreover, probing the breakdown via inner and outer edges reveals a breakdown in discontinuous steps characterized by exactly the Landau level spacing. These results are the first-time evidence for a resonant quantum tunneling mechanism realized through aligning the edge and bulk energy levels. We also explored the fundamental physics of graphene-based devices with an eye focused on possible applications as ultra-high gain and quantum efficiency hybrid graphene-quantum dots phototransistors. We have confirmed that natural graphene presents better transport properties as mobility (10-fold higher) and delta point closer to zero. Also we have been able to observe the anomalous quantum Hall effect, unique to graphene, symbol of the high quality of the device. More experimental work is needed to gain more insights on the real efficiency of the devices and a more efficient fabrication.
Download or read book Mesoscopic Electron Transport written by Lydia L. Sohn and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Nonequilibrium Electron Transport in Quantum Dot and Quantum Point Contact Systems written by Anasuya Erin Krishnaswamy and published by . This book was released on 1999 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Much experimental research has been performed in the equilibrium regime on individual quantum dots and quantum point contacts (QPCs). The focus of the research presented here is electron transport in the nonequilibrium regime in coupled quantum dot and QPC systems fabricated on AlGaAs/GaAs material using the split gate technique. Near equilibrium magnetoconductance measurements were performed on a quantum dot and a QPC. Oscillations were seen in the conductance of the sensor which corresponded to Aharonov-Bohm oscillations in the quantum dot, to our knowledge the first such observation. Sudden jumps in the conductance of the QPC were observed under certain gate biases and under certain magnetic fields. When the gate biases and magnetic field were held constant and the conductance was observed over time, switching was observed with the form of a random telegraph signal (RTS). RTS switching is usually attributed to charging of a single impurity. However, in this case switching may have been due to tunneling via edge states in the dot. Nonequilibrium transport in single quantum dots was investigated. A knee or kink was observed in the current-voltage characteristics of two dots on different material. The bias conditions under which the knee occurred point to electron heating as the physical mechanism for the observed behavior. However, the data can not be fit accurately over all bias ranges with an energy balance hot electron model. Modifications to the model are needed to accurately represent the devices studied here. Finally, the effect of nonlinear transport through a one dimensional (1D) QPC on the equilibrium conductance of an adjacent OD quantum dot was explored. This was the first attempt to observe Coulomb drag between a OD and 1D system. It was observed that the equilibrium conductance peaks in the quantum dot were broadened as the current in the QPC increased. This apparent electron heating effect in the dot can be explained by a simple ballistic phonon model. However, reasonable phase coherence times can be estimated from peak fitting using a Breit- Wigner formula which points to a Coulomb interaction. More detailed numerical calculations should illuminate the dominant scattering processes.
Download or read book CURRENT CONSERVING AC QUANTUM written by 郭榮忠 and published by Open Dissertation Press. This book was released on 2017-01-27 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Current Conserving AC Quantum Transport in Two-dimensional Mesoscopic Systems" by 郭榮忠, Wing-chung, Kwok, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3122104 Subjects: Mesoscopic phenomena (Physics) Electric currents
Download or read book Proceedings of the 7th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology written by Yoshimasa A. Ono and published by World Scientific. This book was released on 2002 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses fundamental problems in quantum physics, with emphasis on quantum coherence and decoherence. Papers coveting the wide range of quantum physics are included: atom optics, quantum optics, quantum computing, quantum information, cryptography, macroscopic quantum phenomena, mesoscopic physics, physics of precise measurements, and fundamental problems in quantum physics. The book will serve not only as a good introduction to quantum coherence and decoherence for newcomers in this field, but also as a reference for experts.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Nanophysics written by Klaus D. Sattler and published by CRC Press. This book was released on 2010-09-17 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intensive research on fullerenes, nanoparticles, and quantum dots in the 1990s led to interest in nanotubes and nanowires in subsequent years. Handbook of Nanophysics: Nanotubes and Nanowires focuses on the fundamental physics and latest applications of these important nanoscale materials and structures. Each peer-reviewed chapter contains a broad-
Download or read book Unconventional Superconductors written by Gernot Goll and published by Springer Science & Business Media. This book was released on 2006 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a comprehensive summary of experiments that are especially suited to reveal the order-parameter symmetry of unconventional superconductors. It briefly introduces readers to the basic theoretical concepts and terms of unconventional superconductivity, followed by a detailed overview of experimental techniques and results investigating the superconducting energy gap and phase, plus the pairing symmetry. This review includes measurements of specific heat, thermal conductivity, penetration depth and nuclearmagnetic resonance and muon-spin rotation experiments. Further, point-contact and tunnelling spectroscopy and Josephson experiments are addressed. Current understanding is reviewed from the experimental point of view. With an appendix offering five tables with almost 200 references that summarize the present results from ambient pressure heavy-fermion and noncopper-oxide superconductors, the monograph provides a valuable resource for further studies in this field.
Download or read book Optical Absorption in a Two dimensional Quantum Point Contact written by Anna Grincwajg and published by . This book was released on 1993 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Foundations Of Quantum Mechanics In The Light Of New Technology Proceedings Of The 7th Intl Symp Isqm tokyo 01 written by Kazuo Fujikawa and published by World Scientific. This book was released on 2002-10-23 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses fundamental problems in quantum physics, with emphasis on quantum coherence and decoherence. Papers covering the wide range of quantum physics are included: atom optics, quantum optics, quantum computing, quantum information, cryptography, macroscopic quantum phenomena, mesoscopic physics, physics of precise measurements, and fundamental problems in quantum physics.The book will serve not only as a good introduction to quantum coherence and decoherence for newcomers in this field, but also as a reference for experts.
Download or read book Quantum Transport of Two dimensional Electronic Systems in a Magnetic Field written by Manhua Leng and published by . This book was released on 1994 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Transport in Semiconductor Submicron Structures written by B. Kramer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Theoretical Study of Transport Through a Quantum Point Contact written by E. Tekman and published by . This book was released on 1990 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Conference on Simulation of Semiconductor Processes and Devices written by and published by . This book was released on 2002 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:
