Carrier dynamics between delocalized and localized states in type-II GaAsSb/GaAs quantum wells

Nonthermal carrier dynamics in Al Ga As/GaAs quantum wells

We present new time-resolved measurements that demonstrate the effect of injected carrier densities on carrier–carrier scattering rates of highly nonequilibrium carrier distributions in the p-doped Al Ga As/GaAs quantum wells with well 0.32 0.68 10 22 width of 5 and 3 nm. The spectra at high densities ( $ 10 cm ) demonstrate that the initially narrow electron distribution is altered in a time l...

Dynamics of localized excitons in InGaN/GaN quantum wells

Symmetry-enhanced supertransfer of delocalized quantum states

Coherent hopping of excitation relies on quantum coherence over physically extended states. In this work, we consider simple models to examine the effect of symmetries of delocalized multi-excitation states on the dynamical timescales, including hopping rates, radiative decay and environmental interactions. While the decoherence (pure dephasing) rate of an extended state over N sites is compara...

Localized and delocalized plasmons in metallic nanovoids

Nanostructured metal films comprised of periodically arranged spherical voids are grown by electrochemical deposition through a self-assembled template. Detailed measurements of the angleand orientation-dependent reflectivity for different sample geometries reveal the spectral dispersion of several different types of surface plasmon modes. The dependence of the energies of both delocalized Brag...

Measurement and modeling of ultrafast carrier dynamics and transport in germanium/silicon-germanium quantum wells.

We measure the intervalley scattering time of electrons in the conduction band of Ge quantum wells from the direct Γ valley to the indirect L valley to be ~185 fs using a pump-probe setup at 1570 nm. We relate this to the width of the exciton peak seen in the absorption spectra of this material, and show that these quantum wells could be used as a fast saturable absorber with a saturation fluen...