ABSTRACT
The history of the polaron begins nearly with the onset of the development of modern, solid state physics. Polaron physics has also found applications in several other areas like organic polymers and biological physics. The idea of the polaron was originally mooted by Landau. In a somewhat different context, namely in an attempt to explain F-centres, he introduced the concept of electron self-trapping. The idea was that an electron, by its Coulomb interaction with the ions of an ionic crystal, produces a distortion or polarization in the lattice. The polarization in turn constitutes a potential well for the electron. In the dynamical case, the polaron size extends over many lattice sites and the lattice can be considered as a continuous medium. Austin and Mott have studied the small polaron problem in some detail, particularly in connection with the conduction mechanism in oxide semiconductors in the presence of disorder.
