Resonances in GaAs/AlxGa1-xAs heterojunctions due to Si shallow donors related protrusions

We investigate the role of protrusions due to individual Si shallow donors on the electron transmission properties through GaAs/AlxGa1-xAs heterojunct ions. Our theoretical calculations show that the protrusions can change rem arkably the electron transmission properties, being even capable of produci ng resonances. The modifications on the electron transmission are stronger when the individual dopant is localized in the AlxGa1-xAs alloy side, but t hey also depend how far is the individual dopant from the GaAs/AlxGa1-xAs h eterojunction interface. When the existence of two simultaneous individual dopants is considered, the electron transmission can present more than one resonance peak.