Laser Spectroscopy and Quantum Optics in GaAs and InAs Semiconductor Quantum Dots

This chapter reviews primarily the evolution of the understanding of coherent optical interactions and spectroscopy in semiconductor quantum dots. The work begins by a brief review of the dominance of complex many-body interactions in higher dimensional materials and then proceeds to examine the behavior in quantum dots. The work reviews the knowledge extracted using frequency domain spectroscopy techniques, which has provided considerable insight into the physics of these systems. The results show that quantum confinement suppresses the kind of many-body physics seen in bulk material and allows the optical interaction to be well described by two or few state energy-level diagrams and the master equations using the density matrix. Numerous examples of classical atomic behavior are reviewed including Rabi oscillations, coherent population trapping, and the Mollow absorption spectrum. The chapter also discusses how these structures can be used as a platform for possible applications to quantum information sciences. Finally, the chapter concludes by examining the role of the hyperfine interaction. Unlike atomic systems with one nucleus, quantum dot excitons involve of order 104 nuclei. The hyperfine interaction is the origin of decoherence of the spin doublet ground state in a negatively charged quantum dot. However, the optical studies have shown an unexpected coupling between the exciton and the nuclei that leads to freezing of the nuclear fluctuations.