Classical frustration and quantum disorder in spin-orbital models
  The most elementary of all physical spin-orbital models is the Kugel-Khomskii model describing a S=1/2, $e_g$ degenerate Mott-insulator. Recent theoretical work is reviewed revealing that the classical limit is characterized by a point of perfect dynamical frustration. It is suggested that this might give rise to a quantum disordered ground state. 
J. Zaanen, L.F. Feiner, and A.M. Oles