We consider a generic polytype double-quantum-well structure where it is possible to achieve a resonance between a spatially direct exciton (both the electron and hole are confined in the same well) and a spatially indirect exciton that has the hole in the same Valence subband, but the electron localized in the other quantum well. Since the two excitons are coupled through electron tunneling, the true excitonic eigenstates are direct-indirect hybrids. We have calculated the nonlinear optical susceptibility of such a system, including both charge-transfer and many-body effects. We have applied our model to the polytype AlSb/InAs/AlSb/GaSb/AlSb structure. The hybrid excitons show enhanced optical nonlinearities because of the charge-transfer character of the indirect exciton and the large oscillator strength of the direct one.
Excitonic resonant self-electro-optic-device configuration in polytype double-quantum-well structures
LA ROCCA, Giuseppe Carlo
1998
Abstract
We consider a generic polytype double-quantum-well structure where it is possible to achieve a resonance between a spatially direct exciton (both the electron and hole are confined in the same well) and a spatially indirect exciton that has the hole in the same Valence subband, but the electron localized in the other quantum well. Since the two excitons are coupled through electron tunneling, the true excitonic eigenstates are direct-indirect hybrids. We have calculated the nonlinear optical susceptibility of such a system, including both charge-transfer and many-body effects. We have applied our model to the polytype AlSb/InAs/AlSb/GaSb/AlSb structure. The hybrid excitons show enhanced optical nonlinearities because of the charge-transfer character of the indirect exciton and the large oscillator strength of the direct one.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
