论文标题
两种频段哈伯德模型中的旋转和电荷波动
Spin and charge fluctuations in the two-band Hubbard model
论文作者
论文摘要
Cuo $ _2 $ Cuprate Perovskites飞机的模型，其中包含$ d_ {x^2-y^2} $铜轨道和氧$p_σ$ orbitals的对称组合。这种方法使人们可以考虑载体与所有范围的自旋和电荷波动的相互作用。 Green功能的派生方程是为对应于孔和电子掺杂的库酸盐的一组参数的求解的。结果表明，上述相互作用导致旋转极性子的出现 - 载体激发的载体状态，这表明自己是状态密度的尖峰和在费米水平上的光谱函数。孔和电子掺杂非常不对称。特别是，这表明了电子掺杂的情况的抗铁磁反应，以及用于孔掺杂的不超量磁有序。在后一种情况下，不可通信的参数随掺杂而生长。双人占用率表明，掺杂电子系统的浓度为0.23，而对于孔掺杂相关性衰减的浓度迅速。这些结果与丘比特的实验观察结果一致。
A model of CuO$_2$ planes of cuprate perovskites, containing $d_{x^2-y^2}$ copper orbitals and symmetric combinations of oxygen $p_σ$ orbitals, is investigated using the strong coupling diagram technique. This approach allows one to take into account the interactions of carriers with spin and charge fluctuations of all ranges. Derived equations for Green's function are self-consistently solved for the set of parameters corresponding to hole- and electron-doped cuprates. It is shown that the mentioned interactions lead to the appearance of spin polarons -- bound states of carriers with spin excitations, which show themselves as sharp peaks of the density of states and spectral functions at the Fermi level. Hole and electron doping are strongly asymmetric. This, in particular, manifests itself in the antiferromagnetic response for the electron-doped case and in an incommensurate magnetic ordering for hole doping. In the latter case, the incommensurability parameter grows with doping. The double occupancy shows that the electron-doped system retains strong correlations up to the concentration 0.23, while for hole doping the correlations decay rapidly. These results are in agreement with experimental observations in cuprates.
