Recombination dynamics of Landau levels in an InGaAs/InP quantum well

The dynamics of differently spin-polarized carriers photoexcited in a system of Landau levels is investigated in an InGaAs/InP quantum well. Shake-up emission from Landau levels above the Fermi level is observed, and it is shown to significantly affect the recombination dynamics of Landau levels. The shake-up effect is found to occur due to the inter-Landau-level scattering, which manifests itself in a rapid decay of the emission from Landau levels. In addition, the inter-Landau-level scattering is shown to determine the time delay of photoluminescence response due to the relaxation of photoexcited electrons among Landau levels. The sharp minimum of the recombination time is observed between the quantum Hall phases with the filling factors $\ensuremath{\nu}=1$ and 2, and it is attributed to the formation of the metallic intermediate phase, which causes increasing overlap between the electron and hole wave functions.