Long lived coherence in self-assembled quantum dots.
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.
Birkedal
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D
Research Center COM, Technical University of Denmark, DK-2800 Kogens Lyngby, Denmark. Birkedal@com.dtu.dk
Leosson
K
K
Hvam
J M
JM