Electronic coupling effects in self-assembled InAs quantum dots

Abstract Electronic coupling effects in self-assembled InAs quantum dots are investigated using capacitance and far-infrared (FIR) spectroscopy. Coupling between different dot-layers is studied using capacitance spectroscopy on samples with double-layers of vertically aligned quantum dots. A strong electrostatic dot–dot interaction reveals itself in distinct shifts of the many particle ground state energy. The fact that the line widths of the FIR resonances are typically a factor of 3 narrower than expected from the inhomogenous broadening due to size fluctuations of the dots is attributed to lateral coupling between the dots within the plane of the dot ensemble.