Theory of indirect exciton photoluminescence in elevated quantum trap

• We investigate the indirect exciton photoluminescence in the evaluated trap.
• The particle distributions of different states are governed by phonon necklace effect.
• The excitons are found to be in two discrete states.
• The nonlinear interaction between excitons is repulsive in the evaluated trap.

Inspired by an experiment of indirect excitons photoluminescence (PL) in elevated quantum trap (High et al., 2009), we theoretically investigate the energy relaxation and nonlinear interactions of indirect excitons in coupled quantum wells. It is shown that, when increasing the laser power, the intensity reversion of two PL peaks is due to the phonon necklace effect. In addition, we use a nonlinear Schrödinger equation including attractive two-body, repulsive three-body interactions and the excitation power dependence of energy distribution to understand the exciton states. This model gives a natural account for the PL blue shift with the increase of the excitation power. This study thus provides an alternative way to understand the underlying physics of the exciton dynamics in coupled potential wells.

Theoretical studies of the exciton dynamics in elevated quantum trap. The phonon necklace effect is found to cause the intensity reversion of two photoluminescence peaks when increasing the laser power. Further taking nonlinear interaction, the excitation energy dependence of photoluminescence shifts was also well explained. Figure optionsDownload as PowerPoint slide