2023/01/26 by Т. С. Шамирзаев, Shamirzaev, T. S., A. V. Shumilin +13 · 1 citation
Engineering · Physics and Astronomy · #Advanced Research in Systems and Signal Processing #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices
paper · pdf · doi:10.48550/arxiv.2301.11138
openalex publication_date 2023/01/26 · openalex created_date 2023/01/28 · openalex updated_date 2026/07/28
The exciton recombination and spin dynamics in (In,Al)As/AlAs quantum dots (QDs) with indirect band gap and type-I band alignment are studied. The negligible (less than 0.2~μeV) value of the anisotropic exchange interaction in these QDs prevents a mixing of the excitonic basis states with pure spin and allows for the formation of spin polarized bright excitons for quasi-resonant circularly polarized excitation. In a longitudinal magnetic field, the recombination and spin dynamics of the excitons are controlled by the hyperfine interaction between the electron and nuclear spins. A QD blockade by dark excitons is observed in magnetic field eliminating the impact of the nuclear spin fluctuations. A kinetic equation model, which accounts for the population dynamics of the bright and dark exciton states as well as for the spin dynamics, has been developed, which allows for a quantitative description of the experimental data.