Exciton fine structure and spin/valley dynamics in nanosystems (Presentation Recording)

Abstract

In my invited talk the fine structure of neutral and charged excitons for GaAs/AlGaAs quantum dots (QDs) grown on (111) plane as well for transition metal dichalcogenides (TMDCs) monolayers will be discussed. These, at first glance, different systems posses similar trigonal symmetry, which makes exciton fine structure and spin dynamics unusual compared with standard low-dimensional semiconductors. The effects of long-range exchange interaction induced mixing of excitons in two valleys of TMDCs and of magneto-induced mixing of bright and dark excitonic states in trigonal QDs are predicted and confirmed experimentally. Manifestations of excitonic spin/valley dynamics in photoluminescence, pump-probe Kerr rotation and spin noise are discussed. The presentation will be based on the following references: [1] G. Sallen, B. Urbaszek, M. M. Glazov, et al., Dark-Bright Mixing of Interband Transitions in Symmetric Semiconductor Quantum Dots, Phys. Rev. Lett. 107, 166604 (2011). [2] L. Bouet, M. Vidal, T. Mano, N. Ha, T. Kuroda, M. V. Durnev, M. M. Glazov, et al., Charge tuning in [111] grown GaAs droplet quantum dots, Appl. Phys. Lett. 105, 082111 (2014). [3] M. M. Glazov, et al., Exciton fine structure and spin decoherence in monolayers of transition metal dichalcogenides Phys. Rev. B 89, 201302(R) (2014). [4] C. R. Zhu, K. Zhang, M. Glazov, et al., Exciton valley dynamics probed by Kerr rotation in WSe2 monolayers, Phys. Rev. B 90, 161302(R) (2014).