Transport through an isolated artificial molecule formed from stacked self-assembled quantum dots

In English We investigate resonant tunneling through two coupled self-assembled quantum dots. The strong confinement and the high crystalline quality provided by the self-assembled dots, in combination with the tunneling coupling between the dots, create a system that may be thought of as an artificial molecule. We are able to isolate one single artificial molecule and detailed investigations of the electrical properties are performed. Peak-to-valley ratios above 1000 and full width half maximum of a few millivolts are measured at 4 K. By changing the temperature we also observe Coulomb blockade effects in a different way. (C) 2003 American Institute of Physics.