M.Sc Thesis


M.Sc StudentShlomo Alon-Braitbart
SubjectMagneto-optical Studies of Single Semiconductor Quantum
Dots in Microcavity
DepartmentDepartment of Physics
Supervisors Full Professors Gershoni David
Professor Emeritus Ehrenfreund Eitan


Abstract

This thesis describes experimental magneto-optics study of neutral and charged excitons confined in single self assembled InAs/GaAs quantum dots, which are embedded in resonant optical microcavity.

                The studied neutral and charged excitonic transitions originate both from the same QD. And they are studied simultaneously, under the same conditions. This enables direct comparison between their physical parameters. Surprisingly, we where able to observe forbidden optical transition, due to recombination from electron hole states in which their spin projection on the magnetic field direction are mainly parallel. This observation, from both charged states, enabled us to fully characterize the excitonic fine structure and to measure the electron and hole g-factors. The measured results are favorably compared with a many carriers theoretical model which includes, the exchange interaction between all the participating electron hole pairs.

                One of the important goals of the research was to construct a novel fiber optics based experimental setup capable of cryogenic measurements of polarization sensitive, low light level emission from quantum structures under the controlled application of external electric and magnetic fields. The thesis describes this effort and the resulting experimental setup, which enabled this novel magneto-optical research.