Sara Ghotb

High temperature superconductors

One of the most successful description of electrons in solid is band theory which is based on reducing many body interactions to an effective one body description. However, there are various situation where band theory fails and the most known one is Mott insulator. According to the band theory we know that odd number of electrons per unit cell should give you a metal. For instance band theory prediction for CoO is to be a metal because it has odd number of electrons however it is an insulator. So band theory fails which means single particle image is not valid for all problems and we need to consider interaction effects as well. This is a great motivation for studying HM which is the simplest model that describes the electron in the lattice.