Ring-shaped spatial pattern of exciton luminescence formed due to the hot carrier transport in a locally photoexcited electron-hole bilayer

摘要

A consistent explanation of the formation of a ring-shaped pattern of excitonluminescence in GaAs/AlGaAs double quantum wells is suggested. The patternconsists of two concentric rings around the laser excitation spot. It is shownthat the luminescence rings appear due to the in-layer transport of hot chargecarriers at high photoexcitation intensity. Interestingly, one of two causes ofthis transport might involve self-organized criticality (SOC) that would be thefirst case of the SOC observation in semiconductor physics. We test this causein a many-body numerical model by performing extensive molecular dynamicssimulations. The results show good agreement with experiments. Moreover, thesimulations have enabled us to identify the particular kinetic processesunderlying the formation of each of these two luminescence rings.