@article {6092,
	title = {Z2 spin-orbital liquid state in the square lattice Kugel-Khomskii model},
	journal = {Physical Review B - Condensed Matter and Materials Physics},
	year = {2009},
	doi = {10.1103/PhysRevB.80.064413},
	author = {Fa Wang and Ashvin Vishwanath}
}
