Electronic structure of multilayer graphene
  We study the electronic structure of multilayer graphene using a $\pi$-orbital continuum model with nearest-neighbor intralayer and interlayer tunneling. Using degenerate state perturbation theory, we show that the low-energy electronic structure of arbitrarily stacked graphene multilayers consists of chiral pseudospin doublets with a conserved chirality sum. 
Hongki Min, A.H. MacDonald