Line narrowing in single semiconductor quantum dots: Toward the control of environment effects

We report systematic linewidth measurements on the fundamental transition of single InGaAs quantum dots. We demonstrate the quenching of the acoustic-phonon dephasing for quantum dots spectrally well separated from the band tail of the wetting layer. We achieve a line narrowing with linewidth of the order of few $\mu \mathrm{eV}$ by tailoring the influence of the electrostatic environment through a decrease of the excess energy in the nonresonant excitation process.