Nonequilibrium carrier dynamics in self‐assembled InGaAs quantum dots

Abstract

PACS 78. 47.+p, 78.67.Hc Carrier dynamics in InGaAs/GaAs quantum dots is analyzed with highly sensitive femtosecond transmission spectroscopy. In a first step, measurements on a large ensemble of nanoislands reveal the dynamical electronic filling of quantum dots from the surrounding wetting layer. Most interestingly, we find a spinpreserving phonon mediated scattering into fully localized states within a few picoseconds. Then, individual artificial atoms are isolated with metallic shadow masks. For the first time, a single self-assembled quantum dot is addressed in an ultrafast transmission experiment. We find bleaching signals in the order of 10-that arise from individual interband transitions of one quantum dot. As a result, we have developed an ultrafast optical tool for both manipulation and read-out of a single self-assembled quantum dot.

Carrier‐carrier and carrier‐phonon scattering in the low‐density and low‐temperature regime for resonantly pumped semiconductor quantum dots

“…[1,2]. A variety of interaction processes is discussed in conjunction with the question whether the phonon bottleneck exists, which originally was predicted from perturbational arguments for a situation, where the level spacing between QD states does not match the LO phonon energy.…”