ABSTRACT
The picture of the polaron conceived by Frohlich is again that of a complex consisting of an electron and the lattice distortion induced by it, but unlike the case of Landau-Pekar polaron, the complex can be found anywhere in the lattice. The Frohlich model considers a low-lying or a slow electron so that the de Broglies wavelength is much larger than the lattice constant, and in this limit, the structure of the lattice becomes unimportant and lattice can be considered to be a continuum. In the Frohlich polaron model, one considers an extra slow electron in the conduction band of the crystal that interacts with the fields associated with the aforementioned polarization vectors to give rise to the electron-phonon Hamiltonian relevant for the polaron problem. Because the electron is low-lying, it will have a large de Broglie wave length associated with it.
