Band-Edge Exciton Fine Structure of Single CdSe-ZnS Nanocrystals in External Magnetic Fields

Louis Biadala (1) , Yann Louyer (1) , Philippe Tamarat (1) , Brahim Lounis (1)

1 CPMOH - Centre de physique moléculaire optique et hertzienne

We report a spectroscopic study of the two lowest-energy exciton levels of individual CdSe-ZnS nanocrystals under applied magnetic fields. Field-induced coupling between the bright and the dark excitonic states is directly observed in the low-temperature photoluminescence spectrum and decay and allows the determination of the angle between the nanocrystal c axis and the field. Orientation-dependent Zeeman splittings of the dark and bright exciton sublevels are measured and provide the corresponding exciton Landé factors, as well as spin-flip relaxation rates between Zeeman sublevels.

Mots clés: single nanocrystals; exciton fine structure; Zeeman splittings

Domaines: Optique [physics.optics]; Physique Quantique [quant-ph]

Louis Biadala, Yann Louyer, Philippe Tamarat, Brahim Lounis. Band-Edge Exciton Fine Structure of Single CdSe-ZnS Nanocrystals in External Magnetic Fields. Physical Review Letters, 2010, 105, pp.157402. ⟨10.1103/PhysRevLett.105.157402⟩. ⟨hal-00611555⟩