Quantum Dots

ISBN-13: 9783642720048 / Angielski / Miękka / 2012 / 176 str.

Lucjan Jacak; Pawel Hawrylak; Arkadiusz Wojs

Opis

We present an overview of the theoretical background and experimental re- sults in the rapidly developing field of semiconductor quantum dots - systems 8 6 of dimensions as small as 10- -10- m (quasi-zero-dimensional) that contain a small and controllable number (1-1000) of electrons. The electronic structure of quantum dots, including the energy quan- tization of the single-particle states (due to spatial confinement) and the evolution of these (Fock-Darwin) states in an increasing external magnetic field, is described. The properties of many-electron systems confined in a dot are also studied. This includes the separation of the center-of-mass mo- tion for the parabolic confining potential (and hence the insensitivity of the transitions under far infrared radiation to the Coulomb interactions and the number of particles - the generalized Kohn theorem) and the effects due to Coulomb interactions (formation of the incompressible magic states at high magnetic fields and their relation to composite jermions), and finally the spin-orbit interactions. In addition, the excitonic properties of quantum dots are discussed, including the energy levels and the spectral function of a single exciton, the relaxation of confined carriers, the metastable states and their effect on the photoluminescence spectrum, the interaction of an exciton with carriers, and exciton condensation. The theoretical part of this work, which is based largely on original re- sults obtained by the authors, has been supplemented with descriptions of various methods of creating quantum-dot structures.

Spis treści

1. Introduction.- 2. Creation and Structure of Quantum Dots.- 3. Single-Particle States of Quantum Dots.- 4. Properties of an Interacting System.- 5. Intraband Optical Transitions.- 6. Interband Optical Transitions.- 7. Capacitance Spectroscopy.- 8. Description of the Properties of Self-Assembled Quantum Dots Within the Band-Structure Model.- 9. Description of a Many-Electron Quantum Dot with the Inclusion of the Spin-Orbit Interaction.- 10. Description of an Exciton in a Quantum Dot Within the Effective-Mass Approximation.- References.

Blurb

The book contains an up-to-date overview of the physics and technology of the man-made artificial atoms, i.e. the quantum dots. Different methods of creation of quantum dots, and the mechanism of carrier confinement in these structures are described. Discussed are the fundamental properties of these quasi-zero-dimensional many-electron systems, such as the single-particle energy quantization, generalized Kohn theorem, the effects due to electron-electron and spin-orbit interactions, magic states and the composite fermion formation in high magnetic fields, and the interaction of a dot with the visible and far-infrared light. The review of experiments carried out on quantum dots includes the capacitance, photoluminescence, and far-infrared spectroscopies. The original part contains the detailed analysis of the atomic-like properties of self-assembled quantum dots (shell structure, Hund rules, exciton condensation), the discussion of the effects due to the spin-orbit interaction (revealed in capacitance and far-infrared spectroscopies), and the description of the structure of luminescence spectrum of a quantum dot in terms of metastable excitonic states (also in a magnetic field).