High magnetic field investigations of quantum dots

We have performed systematic investigations of the Coulomb blockade oscillations observed in a single quantum dot defined in the plane of a two-dimensional electron gas. At high magnetic fields these oscillations reflect the inner electronic structure of the dot, showing both a significant periodic amplitude modulation as well as a systematic variation of the conductance oscillation period. The former results from the modulation of the coupling of the electronic states in the dot with the leads, and can be readily explained within an activated transport model. The latter effect reflects the detailed electronic structure of the quantum dot and permits a comparison with the structure calculated within a simple capacitance model. The experimental results are in excellent qualitative agreement with the theoretical model, however a detailed quantitative comparison must include both the additional coupling of the dot to its environment as well as the gate voltage dependence of the dot structure itself.PACS: 73.20.Dx; 72.20. My.