Electron relaxation in a quantum dot: Significance of multiphonon processes

Electron relaxation in a GaAs quantum dot is investigated to second order in electron-phonon interactions. Calculation of relaxation rate, as a function of level separation, indicates the significant contribution of LO\ifmmode\pm\else\textpm\fi{}LA processes, which create a window of rapid (subnanosecond) relaxation around the longitudinal-optical phonon energy. This result may provide a possible solution to the problem of photoluminescence degradation in small quantum dots.