Hi Everyone, I was curious as to what the most current model in solid state physics is. I've studied the Einstein and Debye Models in Stat Mech, as well as free electron and tight binding models in an intro solid state class, but these models are rather old(which does not imply they are useless). I am in a lab doing research as an undergrad, specifically dealing with semiconductors and phonons, and I wanted to learn about the more modern theories. I think seeing the "state of the art" theory and then working backwards in time to a model which is simpler to work in and understand would be useful. Thanks!