We report the first direct measurements of dephasing in III-V semiconductor quantum dots at low temperature using degenerate four-wave mixing. At OK, the coherence time is limited by the population lifetime whereas pure dephasing due to exciton-phonon interactions appears only at finite temperatures. We observe a striking discrepancy between the homogenous linewidth derived from the dephasing times and the measured photoluminescene linewidth of individual quantum dots, indicating the presence of an additional inhomogenous broadening mechanism in photoluminescence measurements of single quantum dots.
|Publication status||Published - 2002|
|Event||19th Nordic Semiconductor Meeting - Gentofte, Denmark|
Duration: 20 May 2001 → 23 May 2001
Conference number: 19
|Conference||19th Nordic Semiconductor Meeting|
|Period||20/05/2001 → 23/05/2001|