Dynamics of electrons interacting with phonons in quantum dots

Electrons in semiconductors interact mainly with two distinct types of phonons; quasi-discrete LO phonons and the continuous-spectrum LA phonons, the interaction with the latter being much weaker. If the electronic spectrum is continuous (i.e., dimension /spl ges/1), the electrons are scattered mainly by the LO modes and acoustic phonons are of secondary importance. The situation is expected to be quite different in quantum dots where both the electrons and LO phonons are discrete. Energy conservation may severely limit the available scattering channels: LO modes are significant only near resonance, i.e., when the level separation matches the LO phonon energy; otherwise weak LA phonon scattering will dominate the electron dynamics. We will discuss this interplay between LO-dominant and LA-dominant regimes based on our calculations.