@article{SeiboldSigmundHizhnyakov2011, author = {G{\"o}tz Seibold and Ernst Sigmund and Vladimir Hizhnyakov}, title = {Unrestricted slave-boson mean-field approximation for the two-dimensional Hubbard model}, journal = {Physical review}, volume = {57}, number = {12}, pages = {6937 -- 6942}, year = {2011}, }