Possible ordered states in graphene systems

Graphene is a two dimensional honeycomb lattice of carbon atoms which has recently attracted considerable attention because of rapid experimental progress, and because of its novel physical properties. In this work, we will discuss recent theoretical work in which we have proposed new types of ordered electronic states in graphene bilayers, including pseudospin magnets which show spontaneous charge transfer between two layers, and excitonic superfluids which could have remarkably high transition temperatures. This work will conclude with some speculations on the possibility of radically new types of electronic devices in these systems whose operation is based on collective electronic behavior.