title: Exciton dynamics within the band-edge manifold states: the onset of an acoustic phonon bottleneck.
abstract: Exciton dynamics within the band-edge state manifold of CdSe/ZnS and CdSe/CdS quantum dots (QDs) have been investigated. Low-temperature time-resolved photoluminescence (PL) experiments demonstrate that exciton relaxation is mediated by LO phonons, whereas an acoustic phonon bottleneck is observed for splitting energies lower than the optical phonon energy. This has important implications since the main source affecting exciton dephasing is considered to be a spin-flip process. Our results concur with recent observations of long exciton dephasing times in CdSe/CdS QDs and show a way to engineer nanoparticles with enhanced coherence time, a prerequisite for their use in quantum optical applications.
authors.affiliation: IBM Research -Zurich, Säumerstrasse 4, 8803 Rüschlikon, Switzerland. gra@zurich.ibm.com
authors.forename: Gabriele
authors.initials: G
authors.lastname: Rainò
authors.forename: Iwan
authors.initials: I
authors.lastname: Moreels
authors.forename: Antti
authors.initials: A
authors.lastname: Hassinen
authors.forename: Thilo
authors.initials: T
authors.lastname: Stöferle
authors.forename: Zeger
authors.initials: Z
authors.lastname: Hens
authors.forename: Rainer F
authors.initials: RF
authors.lastname: Mahrt