Landau levels above the optical-phonon continuum in two and three dimensions

Abstract
The position of the Landau levels perturbed by the electron-phonon interaction is calculated for energies above the LO-phonon continuum in two and three dimensions. In addition to the Landau levels at nħωc (ωc is the cyclotron frequency) a series of levels are found at ħω0+lħωc (ω0 is the LO-phonon frequency). The degeneracy between the levels nħωc and ħω0+lħωc is lifted by the LO-phonon interaction. Our results are valid for excitation energies smaller than 2ħω0, for zero temperature, and for weak polar materials.