HIGH MAGNETIC-FIELD INVESTIGATIONS OF QUANTUM DOTS

We have performed systematic investigations of the Coulomb blockade os cillations observed in a single quantum dot defined in the plane of a two-dimensional electron gas. At high magnetic fields these oscillatio ns reflect the inner electronic structure of the dot, showing both a s ignificant periodic amplitude modulation as well as a systematic varia tion of the conductance oscillation period. The former results from th e 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 calculate d within a simple capacitance model. The experimental results are in e xcellent qualitative agreement with the theoretical model, however a d etailed quantitative comparison must include both the additional coupl ing of the dot to its environment as well as the gate voltage dependen ce of the dot structure itself.