Editing Effective field theory (section)

===BCS theory of superconductivity===
Another famous example is the [[BCS theory]] of [[superconductivity]]. Here the underlying theory is the theory of [[electron]]s in a [[metal]] interacting with lattice vibrations called [[phonon]]s. The phonons cause attractive interactions between some electrons, causing them to form [[Cooper pair]]s. The length scale of these pairs is much larger than the wavelength of phonons, making it possible to neglect the dynamics of phonons and construct a theory in which two electrons effectively interact at a point. This theory has had remarkable success in describing and predicting the results of experiments on superconductivity.