Seminars Archive

Artificial Atoms, Molecules and Impurities

Abstract
Vertical quantum dot single electron transistors are ideal for performing atomic-like and molecular-like experiments on artificial semiconductor atoms, molecules, and impurities. The first two are fabricated from special GaAs/AlGaAs/InGaAs heterostructures, and the third from an ensemble of self-assembled dots (SAD`s) embedded in an AlGaAs barrier. The relatively large single and double dot systems contain a tunable number of electrons starting from zero and ground and excited states can be identified by measuring current vs. B-field. A Shell structure and Hund`s first rule are clear for the single dot. The presence of symmetric and anti symmetric states is evident in the double dots. States from a few (<10) of the smaller SAD`s can also be simply classified.