Superconductivity Without Phonons: From Heavy Electrons to the Cuprates and Pnictides

The microscopic mechanism of conventional superconductivity is based upon the interaction between electrons and quantized vibrations  of the crystalline lattice. In contrast, superconductivity in many strongly correlated materials is believed to be caused by interactions of electrons with their own collective excitations. Examples are inter-metallic heavy electron materials, ceramic copper-oxide high-temperature superconductors, organic charge transfer salts or the recently discovered iron based superconductors. We will give an overview of this exciting area of research, emphasizing common themes that offer an explanation for unconventional superconductivity in these  distinct classes of materials.