Two color blinking of single strain-induced GaAs quantum dots

In this letter we report on a temporal instability in the ground and excite d state luminescence of a single strain-induced quantum dot. Using a micros copic photoluminescence technique, we record spectra from a single strain-i nduced 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 obser ved effect two color blinking. (C) 1999 American Institute of Physics. [S00 03-6951(99)02318-9].