Exciton density pattern formation in laser irradiated quantum wells under electrodes of various shapes

Abstract

The condensation of indirect excitons in double quantum wells is studied in an electric field created by electrodes of different shapes. The finite value of the exciton lifetime, the pumping and nonuniformity of the electric field under the electrode are taken into account. It is shown that islands of exciton condensed phase emerge under electrodes when the pumping exceeds a certain threshold value. They appear first under the rim where the potential energy of excitons has a dip. Calculations predict a complicated evolution of the exciton density distribution: from the gaseous phase at low laser intensities to the condensed phase in the whole area under the electrode at larger intensities. Therefore, the configurations of the exciton condensed phase may be manipulated by choosing the setups with conductive electrodes of different shapes via forming specific potentials of the electrical field and controlled by the level of the laser irradiation.

Exciton condensation in quantum wells with defects of macroscopic sizes

“…This model was applied to the explanation of other experiments in which the manifestation of the large exciton density was observed. Thus, the explanations of different patterns in the GaAS/AlGaAs based double quantum wells excited through windows of different shape in metallic electrodes obtained in [16,31] were given in [32][33][34], the peculiarities of the emergence of spatial structures in the luminescence of indirect excitons in a periodic potential obtained in [35] were presented in [36], the explanations of the fracturing of the inner ring around the laser sport [37] were given in the paper [38].…”

Pulses of the Excitonic Condensed Phase in Semiconductors with Double Quantum Well at Steady Pumping

“…The peculiarities of the appearance of a structure in the luminescence of indirect excitons in the presence of a periodic potential [20] were presented in [21]. The structures that arise in the luminescence from double quantum wells with electrodes of the different form [22,23] were explained in [24]. The explanation of the fragmentation of the inner ring in a laser sport observed in [25] was given in [26].…”