Special focus is given to the optical and electronic properties of single quantum dots due to their potential applications in devices operating with single electrons and/or single photons. This includes quantum dots in electric and magnetic fields, cavity-quantum electrodynamics, nonclassical light generation, and coherent optical control of excitons.

Radiationless Transitions is a critical discussion of research studies on the theory and experiments in radiationless transitions. This book is composed of nine chapters, and begins with discussions on the theory and experiment of photophysical processes of single vibronic levels and/or single rovibronic levels. The subsequent chapters deal with the spectroscopic investigations of intramolecular vibrational relaxation; the dynamics of molecular excitation by light; and the photophysical processes of small molecules in condensed phase. The discussions then shift to the high pressure effects on molecular luminescence and the internal conversion involving localized excitations, presenting one qualitative and one quantitative example, as well as the intersystem crossing with localized excitations. A chapter explores the energy transfer processes that occur after a molecule in solution is excited by light, with an emphasis on solid solutions in which the large amplitude molecular motion is largely quenched. This chapter also looks into the liquid solutions in which the molecules can translate and rotate under the influence of fluctuating forces from the liquid. The concluding chapter focuses on ultrafast processes. Researchers in the fields of physics, chemistry, and biology will benefit from this book.

This is the first book to specifically focus on semiconductor nanocrystals, and address their synthesis and assembly, optical properties and spectroscopy, and potential areas of nanocrystal-based devices. The enormous potential of nanoscience to impact on industrial output is now clear. Over the next two decades, much of the science will transfer into new products and processes. One emerging area where this challenge will be very successfully met is the field of semiconductor nanocrystals. Also known as colloidal quantum dots, their unique properties have attracted much attention in the last twenty years.

This thesis work analyses aspects of dissipative quantum dynamics, with a view to look for further possibilities of controlling the dynamics with shaped laser pulses. The first part concerns the problem of efficient population transfer in mesoscopic zero-dimensional solid state systems - InAs quantum dots embedded in GaAs matrix. In these systems the consequences of laser driving induced dissipation of exciton dynamics are analyzed, in relation to adiabatic population transfer. Specifically, the problem of robust creation of exciton and biexciton states are addressed through numerical simulations and analytical approaches using a non-Markovian density matrix based analysis, suitable for dealing with dissipative quantum dynamics under strong laser fields. A physical picture describing phonon induced dissipation among dressed state has emerged as a consistent interpretation of the underlying dynamics. Furthermore, suitable parameter regimes where efficient population transfer can be achieved are proposed. The second part deals with the population transfer to high lying vibrational states of the CO stretching mode of carboxy-hemoglobin molecule in the native protein environment. On the basis of a fluctuating potential for the CO stretching mode, ultrafast pump-probe spectra are simulated using quantum wave packet propagation. To this end, Local Control Theory was employed to find design a set of laser pulses which accomplish the 'vibrational ladder climbing' and selective state preparation despite the detrimental fluctuations induced by the protein environment. These results will be providing benchmarks for the future experimental efforts.