title: Long lived coherence in self-assembled quantum dots.
abstract: We report measurements of ultralong coherence in self-assembled quantum dots. Transient four-wave mixing experiments at 5 K show an average dephasing time of 372 ps, corresponding to a homogeneous linewidth of 3.5 microeV, which is significantly smaller than the linewidth observed in single-dot luminescence. Time-resolved luminescence measurements show a lifetime of the dot ground state of 800 ps, demonstrating the presence of pure dephasing at finite temperature. The homogeneous width is lifetime limited only at temperatures approaching 0 K.
authors.affiliation: Research Center COM, Technical University of Denmark, DK-2800 Kogens Lyngby, Denmark. Birkedal@com.dtu.dk
authors.forename: D
authors.initials: D
authors.lastname: Birkedal
authors.forename: K
authors.initials: K
authors.lastname: Leosson
authors.forename: J M
authors.initials: JM
authors.lastname: Hvam