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

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