Homogeneous line-width of optical transitions and multiple electron-LO-phonon scattering in quantum dots

The optical line-shape of electronic transitions due to the polar electron-LO-phonon interaction in semiconductor quantum dots is studied. The mechanism of the finite optical line-width is based on the multiple electron-LO-phonon scattering. The influence of the higher order corrections beyond the self-consistent Hartree-Fock approximation to the electron-phonon part of the electronic self-energy is estimated quantitatively. The problem is studied within the two-level model of a single electron interacting with the system of longitudinal optical phonons of the whole bulk sample of the polar semiconductor. The influence of the higher order corrections is demonstrated on the line-shape of the optical transitions, the temperature dependence of the line-width and on the dependence of the line-width on the size of the quantum dot.