Observation of the light-hole quantum dots in a strained GaAs quantum well

We observed a light-hole-to-electron transition of strain-induced quantum dots (SIQDs) in a strongly strained GaAs quantum well (QW). Circularly-polarized luminescence excitation spectroscopy showed a pronounced counter-circularly polarized component below the heavy-hole exciton transition in the QW. This special feature can be explained by the existence of the light-hole-to-electron transition at this energy level. On the other hand, a very high co-circular polarization (=0.8) was obtained near the lowest transition of SIQD.