title: Magnetic and pairing properties of a two-orbital model for the pnictide superconductors: a quantum Monte Carlo study.
abstract: Using the constrained-path Monte Carlo method, a two-orbital model for the pnictide superconductors is studied at half filling and in both the electron- and hole-doped cases. At half filling, a stable (π, 0)/(0, π) magnetic order is explicitly observed and the system tends to be in an orthomagnetic order rather than the striped antiferromagnetic order on increasing the Coulomb repulsion U. In the electron-doped case, the (π, 0)/(0, π) magnetic order is enhanced upon doping and suppressed eventually and a s(±) pairing state dominates all the possible nearest-neighbour-bond pairings. Whereas in the hole-doped case, the magnetic order is straightforwardly suppressed and two nearly degenerate A(1g) and B(1g) intraband pairings become the dominant ones.
authors.affiliation: Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China.
authors.forename: Guang-Kun
authors.initials: GK
authors.lastname: Liu
authors.forename: Zhong-Bing
authors.initials: ZB
authors.lastname: Huang
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Wang