Ultrafast dynamics of neutral and charged triplet magnetoexcitons in a high-mobility density-tunable GaAs-AlGaAs single quantum well

摘要

By means of spectrally resolved degenerate four-wave mixing spectroscopy, we have investigated a modulation doped AlGaAs/GaAs single quantum well. We obtain dephasing times of neutral and charged excitons, indicating that the charged excitons (trions) are not localized. A quantum beating between trion and exciton line shows that there is no spatial separation between the two.