Department of Physics, Indian Institute of Technology, Kanpur-208016, India.
J Phys Condens Matter. 2011 Aug 10;23(31):312201. doi: 10.1088/0953-8984/23/31/312201. Epub 2011 Jul 8.
Spin wave excitations and the stability of the (0, π) ordered spin density wave (SDW) state are investigated within the minimal two-band model for iron pnictides including a Hund's coupling term. The SDW state is shown to be stable in two distinct doping regimes-for finite hole doping in the lower SDW band for small second-neighbour hoppings, and for low electron doping in the upper SDW band for comparable first-neighbour and second-neighbour hoppings. In both cases, Hund's coupling strongly stabilizes the SDW state due to the generation of additional ferromagnetic spin couplings involving the inter-orbital part of the particle-hole propagator. The spin wave energies for the two-band model are very similar to the one-band t-t' Hubbard model results obtained earlier, and are in agreement with the findings from inelastic neutron scattering studies of iron pnictides.
在包括 Hund 耦合项的铁族磷化物最小双带模型中，研究了自旋波激发和（0，π）有序自旋密度波（SDW）态的稳定性。结果表明，SDW 态在两个不同的掺杂区域是稳定的：对于较小的第二近邻跃迁，在较低的 SDW 带中存在有限的空穴掺杂，以及对于可比的第一近邻和第二近邻跃迁，在较高的 SDW 带中存在低电子掺杂。在这两种情况下，由于涉及粒子-空穴传播子的轨道间部分的额外铁磁自旋耦合的产生，Hund 耦合强烈稳定了 SDW 态。双带模型的自旋波能量与先前获得的单带 t-t'Hubbard 模型结果非常相似，并且与铁族磷化物的非弹性中子散射研究的结果一致。
