Electronic Quantum Transport in Mesoscopic Semiconductor Structures

ISBN-13: 9781441923097 / Angielski / Miękka / 2011 / 270 str.

Thomas Ihn

Opis

The physics of semiconductors has seen an enormous evolution within the last ?fty years. Countless achievements have been made in scienti?c research and device applications have revolutionized everyday life. We have learned how to customize materials in order to tailor their optical as well as electronic properties. The on- ing trend toward device miniaturization has been the driving force on the appli- tion side and it has fertilized fundamental research. Nowadays, advanced processing techniques allow the fabrication of sub-micron semiconductor structures in many university research laboratories. At the same time, experiments down to millikelvin temperatures allow researchers to anticipate the observation of quantum phenomena, so far hidden at room temperature by the large thermal energy and strong dephasing. The ?eld of mesoscopic physics deals with systems under experimental con- tions where several quantum length scales for electrons such as system size and phase coherence length, or phase coherence length and elastic mean free path, are compa- ble. Intense research over the last twenty years has revealed an enormous richness of quantum effects in mesoscopic semiconductor physics, which is typically charact- ized by an interplay of quantum interference and many-body interactions. The most famous phenomena are probably the integer and fractional quantum Hall effects, the quantization of conductance through a quantum point contact, the Aharonov-Bohm effect, and single-electron charging of quantum dots.

Spis treści

Contents Part I Introduction to Electron Transport 1 Electrical conductance: Historical account from Ohm to the semiclassical Drude–Boltzmann theory 2 Toward the microscopic understanding of conductance on a quantum mechanical basis 2.1 Quantum transport in metals 2.2 Transistors and two-dimensional electron gases in semiconductors 2.2.1 Two-dimensional electron gases in field-effect transistors 2.2.2 Resonant tunneling in semiconductors 2.2.3 Integer and fractional quantum Hall effect 2.2.4 Weak localization 2.3 Basic phenomena in semiconductor structures of reduced size and dimensionality 2.3.1 The Aharonov–Bohm effect and conductance fluctuations 2.3.2 Conductance quantization in semiconductor quantum point contacts 2.3.3 Semiconductor quantum dots and artificial atoms Part II Conductance in Strongly Interacting and Disordered Two-Dimensional Systems 3 The concept of metals and insulators 4 Scaling theory of localization 5 Electron–electron interactions within the Fermi-liquid concept 5.1 Dephasing in diffusive two-dimensional systems 5.2 Interaction corrections to the conductivity 5.2.1 Temperature-dependent screening 5.2.2 Interaction corrections due to interference of multiply scattered paths 5.2.3 A comprehensive theory of interaction corrections based on the Fermi liquid concept 6 Beyond Fermi-liquid theory 7 Summary of disorder and interaction effects 8 Experiments on strongly interacting two-dimensional systems and the metal–insulator transition 9 Theoretical work related to the metal–insulator transition 10 Metallic behavior in p-SiGe quantum wells 10.1 Samples and structures 10.2 Scaling analysis, quantum phase transition, and heating effects 10.3 Magnetoresistance measurements 10.4 Weak-localization correction 10.5 Interaction corrections to the conductivity: multipleimpurity scattering 10.6 Interaction corrections of the Drude conductivity due to T-dependent screening 10.7 Reentrant insulating behavior 10.8 Parallel magnetic field 10.9 Discussion of the results and conclusions Part III Electron Transport through Quantum Dots and Quantum Rings 11 Introduction to electron transport through quantum dots 11.1 Resonant tunneling and the quantization of the particle number on weakly coupled islands 11.2 Quantum dot states: from a general hamiltonian to the constant-interaction model 11.3 Transport through quantum dots 11.3.1 Coulomb-blockade oscillations 11.3.2 Coulomb-blockade diamonds 11.3.3 Conductance peak line shape at finite temperatures 11.4 Beyond the constant-interaction model 12 Energy spectra of quantum rings 12.1 Introduction to quantum rings 12.2 Samples and structures 12.3 Magnetotransport measurements on a quantum ring 12.4 Interpretation within the constant-interaction model 12.5 One-dimensional ring model 12.6 Ring with finite width 12.7 Experimental single-particle level spectrum 12.8 Effects of broken symmetry 12.9 Interaction effects and spin-pairing 12.10Coulomb-blockade in a Sinai billiard 12.11Relation of the ring spectra to persistent currents 12.12Summary 13 Spin filling in quantum dots 13.1 Introduction to spins in quantum dots 13.2 Samples and structures 13.3 Experiments 13.4 Weak-coupling regime 13.5 Intermediate-coupling regime 13.6 Strong coupling 13.7 Diamagnetic shift 13.8 Discussion of the results 13.9 Conclusions Part IV Local Spectroscopy of Semiconductor Nanostructures 14 Instrumentation: Scanning force microscopes for cryogenic temperatures and magnetic fields 14.1 Introduction: low-temperature scanning force microscopes 14.2 Design criteria for a low-temperature scanning force microscope for the investigation of semicond

Blurb

This book treats three topics of electronic quantum transport in mesoscopic semiconductor structures: the conductance in strongly interacting and disordered two-dimensional systems and the metal insulator transition, electron transport through quantum dots and quantum rings in the Coulomb-blockade regime, and scanning probe experiments on semiconductor nanostructures at cryogenic temperatures. In addition it gives a brief historical account of electron transport from Ohm's law through transport in semiconductor nanostructures, and a review of cryogenic scanning probe techniques applied to semiconductor nanostructures. Both graduate students and researchers in the field of mesoscopic semiconductors or in semiconductor nanostructures will find this book useful.