Coulomb-coupling in vertically aligned self-assembled InAs quantum dots

Electronic coupling effects in vertically aligned self-assembled InAs quant um dots are investigated using capacitance and far-infrared (FIR) spectrosc opy. Capacitance spectra show distinct shifts of the many-particle ground s tate energies, which is the result of a strong electrostatic dot-dot intera ction. FIR spectroscopy shows that the dynamics of the dot system is only s lightly affected by Coulomb interaction. The dots in the second layer are f ound to have a larger diameter than those in the first.