title: Tailoring the exciton fine structure of cadmium selenide nanocrystals with shape anisotropy and magnetic field.
abstract: We use nominally spheroidal CdSe nanocrystals with a zinc blende crystal structure to study how shape perturbations lift the energy degeneracies of the band-edge exciton. Nanocrystals with a low degree of symmetry exhibit splitting of both upper and lower bright state degeneracies due to valence band mixing combined with the isotropic exchange interaction, allowing active control of the level splitting with a magnetic field. Asymmetry-induced splitting of the bright states is used to reveal the entire 8-state band-edge fine structure, enabling complete comparison with band-edge exciton models.
authors.affiliation: LP2N, Université de Bordeaux , F-33405 Talence, France.
authors.forename: Chiara
authors.initials: C
authors.lastname: Sinito
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Fernée
authors.forename: Serguei V
authors.initials: SV
authors.lastname: Goupalov
authors.forename: Paul
authors.initials: P
authors.lastname: Mulvaney
authors.forename: Philippe
authors.initials: P
authors.lastname: Tamarat
authors.forename: Brahim
authors.initials: B
authors.lastname: Lounis
keywords: CdSe; PL; PLE; exciton fine structure; quantum dot; single nanocrystal