The photoluminescence of quantum dots is studied in a high magnetic field regime where the cyclotron frequency is comparable to the confinement energy. Applying a magnetic field perpendicular to the lateral potential plane lifts the shell degeneracy and magneto-photoluminescence spectroscopy therefore provides a probe to investigate the energy shell structure of quantum dots. By isolating a single quantum dot, the inhomogeneous broadening from a distribution of dot sizes and compositions is eliminated and the fine structure of the spectrum is revealed. The orbital splitting of angular momentum states is shown to follow the Fock-Darwin scheme. However, it is also apparent that each angular momentum branch consists of two distinct lines whose magnetic field evolution cannot be explained by a simple Zeeman spin splitting. The dependence of line splitting on orbital state can be described by the addition of spin-orbit coupling to the Fock-Darwin model. Accordingly, a quantitative measurement of the spin-orbit coupling strength in self-assembled quantum dots is obtained for the first time.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/28029 |
| Date | January 2008 |
| Creators | Vachon, Martin |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 102 p. |
Page generated in 0.002 seconds