Resonant electron and hole tunneling between GaAs quantum wells

Time-resolved photoluminescence measurements in the picosecond regime are reported for a GaAs/Alsub0.35Gasub0.65As asymmetric double quantum well structure biased by electric fields of positive or negative polarity. A large number of electron and hole resonances is detected. A splitting of the ground state resonances reveals the importance of excitonic effects. Longitudinal optical phonon assisted tunneling plays a minor role for narrow quantum wells in comparison with impurity or interface roughness assisted transfer.