Electric field effect in the spin dynamics of self-assembled InAs/GaAs quantum dots

We identify fundamental mechanisms of electron and hole dynamics in self-organized InAs/GaAs quantum dots (QDs) subject to vertical electric fields by photocurrent investigations. We propose a spin-flip mechanism involving a spin exchange between neighboring QDs. The spin-flip process is revealed in the photocurrent dynamics when the exciton population increases unexpectedly with reverse bias.