Evidence of interdot electronic tunneling in vertically coupled In0.4Ga0.6As self-organized quantum dots

摘要: Ultrafast differential transmission spectroscopy with a resonant pump reveals evidence of electronic tunneling among the excited levels vertically aligned In0.4Ga0.6As self-organized quantum dots. This is observed as rapid spectral redistribution electrons within few hundred femtoseconds optical excitation. Measurements show that this spread independent carrier density and, therefore, indicate carrier–carrier scattering not main mechanism for redistribution. Instead, responsible interdot coupling; rate calculations agree reasonably experiment, supporting conclusion.