Spin Dynamics of Neutral and Charged Excitons in InAs/GaAs Quantum Dots

We have studied the spin dynamics in non-intentionally doped and n-modulation doped self-organized InAs/GaAs quantum dots (QD) by time-resolved photoluminescence performed under strictly resonant excitation. We demonstrate that the carrier spins in these nanostructures are totally frozen on the neutral or charged exciton lifetime scale.