Baryon chiral perturbation theory transferred to hole-doped   antiferromagnets on the honeycomb lattice
  A systematic low-energy effective field theory for hole-doped antiferromagnets on the honeycomb lattice is constructed. The formalism is then used to investigate spiral phases in the staggered magnetization as well as the formation of two-hole bound states. 
F.-J. Jiang, F. Kaempfer, B. Bessire, M. Wirz, C. P. Hofmann, and   U.-J. Wiese
cond-mat.str-el hep-ph