Semiconductor Macroatoms: Basic Physics And Quantum-device Applications

✍ Scribed by Fausto Rossi

• Publisher: Imperial College Press
• Year: 2005
• Tongue: English
• Leaves: 332
• Edition: illustrated edition
• Category: Library

✦ Synopsis

This book discusses the basic physics of semiconductor macroatoms at the nanoscale as well as their potential application as building blocks for the realization of new-generation quantum devices. It provides a review on state-of-the art fabrication and characterization of semiconductor quantum dots aimed at implementing single-electron/exciton devices for quantum information processing and communication. After an introductory chapter on the fundamentals of quantum dots, a number of more specialized review articles presents a comprehensive picture of this rapidly developing field, specifically including strongly multidisciplinary topics such as state-of-the-art nanofabrication and optical characterization, fully microscopic theoretical modeling of nontrivial many-body processes, as well as design and optimization of novel quantum-device architectures.

✦ Table of Contents

Contents......Page 8
Preface......Page 6
1.1 Introduction......Page 14
1.2 Structural Information on Quantum Dots......Page 16
1.3.1 Eigenstates in the absence of external perturbations......Page 20
1.3.2.1 Electric field effects......Page 25
1.3.2.2 Magnetic field effects......Page 27
1.3.3 Dot-dot interaction in stacked dots; quantum dot molecules......Page 29
1.4.1 The idealized quantum dot: a two-level atom. Populations and coherence......Page 30
1.4.2 Optical properties of dot ensembles. Broadening and selection rules......Page 32
1.4.3 Single dot spectroscopy: the failure of the simple ideas......Page 34
1.5 Phonons and Carrier Coupling to the Phonons in Quantum Dots......Page 39
1.6 Carrier-Carrier Interaction in Quantum Dots......Page 45
1.6.1 Electron-hole interaction in quantum dots......Page 46
1.6.2 Excitonic complexes and optical properties of highly excited quantum dots: new phenomena and a new approach......Page 49
1.6.3 Auger scattering in quantum dots......Page 52
Acknowledgments......Page 56
Bibliography......Page 57
2.1 Introduction......Page 64
2.1.1 Semiconductor quantum dots......Page 66
2.2 Fabrication and Structural Analysis of InGaAs/GaAs Quantum Dots......Page 67
2.3 Nanotechnological Strategies for the Fabrication of Single-Dot Structures......Page 74
2.4 Modeling of the Carrier Wavefunctions......Page 77
2.5 Photoluminescence Experiments......Page 86
2.6 Single-Dot Spectroscopy......Page 91
2.6.1 Wavefunction spectroscopy......Page 92
2.6.2 Optical spectroscopy......Page 98
Bibliography......Page 106
3.1 Introduction......Page 114
3.2.1 Interface quantum dots......Page 117
3.2.2 Self-assembled quantum dots......Page 120
3.3 Experimental Techniques......Page 127
3.3.1 Coherent spectroscopy on interface quantum dots......Page 128
3.3.2 Coherent spectroscopy on self-assembled quantum dots......Page 132
3.4.1.1 Ultrafast optical nonlinearities of single interface quantum dots......Page 136
3.4.1.2 Optical Stark effect and Rabi oscillations in a quantum dot: ultrafast control of single exciton polarizations......Page 141
3.4.2 Coherent control in single self-assembled quantum dots......Page 151
3.5 Outlook......Page 156
Bibliography......Page 157
4.1 Introduction......Page 164
4.2.1 Semiconductors of higher dimension......Page 165
4.2.2.1 Weak confinement regime......Page 166
4.2.2.2 Strong confinement regime......Page 167
4.2.3 Spin structure......Page 168
4.3.1 Weak confinement regime......Page 170
4.3.2 Strong confinement regime......Page 171
4.4 Few-Partide States......Page 172
4.4.1 Multi excitons......Page 173
4.4.3 Configuration interactions......Page 174
4.5 Optical Spectroscopy......Page 175
4.5.1.1 Weak confinement regime......Page 176
4.5.1.2 Strong confinement regime......Page 177
4.5.2 Multi excitons......Page 178
4.6 Inter-dot Coupling: Tunneling vs. Coulomb Correlations......Page 180
4.7 Inter-Dot Coupling: Role of the Electric Field......Page 188
Bibliography......Page 193
5.1 Introduction......Page 196
5.2 Energy Relaxation in Bulk and Quantum Well Structures......Page 198
5.3 Magneto-Absorption in Quantum Dots: the Evidence of Polarons......Page 205
5.4 Energy Relaxation in the Polaron Framework......Page 220
5.5 Excitonic Polarons in Quantum Dots......Page 222
5.6 Diagonal Non-Perturbative Interaction Between Electrons and Acoustic Phonons......Page 225
Acknowledgments......Page 228
Bibliography......Page 229
6.1 Introduction......Page 234
6.2 Model for Phonon-Induced Pure Dephasing......Page 237
6.3 Analytical Results for Excitations with Ultrafast Pulses......Page 239
6.3.1 Linear single-dot spectra......Page 240
6.3.2 The initial decay of four-wave-mixing signals......Page 243
6.3.3 Impact of pure dephasing on electronic and phononic occupations......Page 247
6.4.1 Phonon-induced damping of Rabi oscillations in quantum dots......Page 250
6.4.2 Optimal gating strategy: a trade-off between different types of decoherence......Page 254
Acknowledgments......Page 257
Bibliography......Page 258
7.1 Introduction......Page 262
7.2.1 Single-dot encoding schemes......Page 265
7.2.2.1 GaAs-based quantum hardware......Page 270
7.2.2.2 GaN-based quantum hardware......Page 275
7.2.3 Combination of charge and spin degrees of freedom......Page 281
7.2.3.1 Artificial molecules as qubits and Raman adiabatic passages for the optical gating......Page 284
7.3 Summary and Conclusions......Page 291
Bibliography......Page 292
8.1 Introduction......Page 296
8.2 Field-Induced Exciton-Exciton Coupling in Semiconductor Quantum Dots with no Intrinsic Bias......Page 299
8.3.1 Engineering electronic structure and optical spectrum in coupled GaN quantum dots......Page 307
8.3.2 Semi-analytical model......Page 310
8.3.2.1 Single exciton system......Page 311
8.3.2.2 Biexciton system......Page 312
8.4.1 Definition......Page 316
8.4.2 Measurement using a STIRAP process......Page 318
8.4.2.1 Failure of the adiabatic condition......Page 321
8.4.2.2 Failure of the energy conservation requirement......Page 323
8.5 All-Optical Read-Out Device......Page 324
Bibliography......Page 328
Index......Page 330