Γ- and <i>X</i>-band contributions to nonresonant tunneling in GaAs/Al0.35Ga0.65As double quantum wells

Abstract

Time-resolved photoluminescence in the picosecond regime is performed on an asymmetric GaAs/Al0.35Ga0.65As double quantum well structure with a barrier thickness of 6 nm to obtain the Γ- and X-point barrier contributions to nonresonant tunneling. Application of hydrostatic pressure up to 37 kbar at 5 K reveals that tunneling via virtual X states is at least 800 times less efficient than via virtual Γ states. Above 24.5 kbar an extremely fast scattering of electrons out of the n=1 quantized level of the narrower quantum well is observed.