Two color blinking of single strain-induced GaAs quantum dots

In this letter we report on a temporal instability in the ground and excited state luminescence of a single strain-induced quantum dot. Using a microscopic photoluminescence technique, we record spectra from a single strain-induced quantum dot in the GaAs/(AlGa)As material system. On a time scale of seconds the luminescence shows an increase and decrease in intensity with an increase of the ground state luminescence correlating with a decrease in the excited state luminescence intensity and vice versa. We term the observed effect two color blinking.