Electronic polaron effects in mixed valence and heavy fermion materials

It is shown that the Coulomb interaction between line-integral electrons and broad band electrons has a profound influence on the dynamical properties of an line-integral hole in mixed valence and heavy fermion materials. At zero temperature the dynamics of the screening process contains an infrared divergence. The broadening of this divergence by temperature causes the motion of the line-integral electrons to crossover from wave propagation to diffusion. This mechanisms explains the observed dual nature of the line-integral electrons, namely that at low temperatures they behave like a Fermi liquid, while at high temperatures they evolve into a localized magnetic moments