论文标题
带有抗铁磁的hund耦合的三轨哈伯德模型的熵和电子订单
Entropy and electronic orders of the three-orbital Hubbard model with antiferromagnetic Hund coupling
论文作者
论文摘要
多型哈伯德系统中的抗磁性hund耦合会引起轨道冷冻和相关的超导不稳定，以及在奇数轨道的情况下，唯一的复合订单。虽然最近详细探讨了半填充三轨模型的丰富相图，但掺杂系统的性质仍有待阐明。在这里，我们通过计算半填充模型的熵来补充先前的研究，该模型表现出轨道冻干区域的增加，并在复合有序相中的抑制作用。掺杂依赖的相图表明，如果常规的电子订单被挫败抑制，则可以在掺杂的Mott状态下稳定复合有序状态。尽管Antiferro轨道订单在填充范围$ 2 \ lyssim n \ le 3 $中占主导地位，而铁轨道订单则以$ 1 \ sillsim n <2 $为$ 1 \ lyssim n <2 $，但我们发现超导性具有非常高的$ t_c $ agiply $ t_c $ about $ n = 1.5 $（季度填充）。同样在掺杂系统中，轨道冻结的交叉和超导性之间也有密切的联系。
An antiferromagnetic Hund coupling in multiorbital Hubbard systems induces orbital freezing and an associated superconducting instability, as well as unique composite orders in the case of an odd number of orbitals. While the rich phase diagram of the half-filled three-orbital model has recently been explored in detail, the properties of the doped system remain to be clarified. Here, we complement the previous studies by computing the entropy of the half-filled model, which exhibits an increase in the orbital-frozen region, and a suppression in the composite ordered phase. The doping dependent phase diagram shows that the composite ordered state can be stabilized in the doped Mott regime, if conventional electronic orders are suppressed by frustration. While antiferro orbital order dominates the filling range $2\lesssim n \le 3$, and ferro orbital order the strongly interacting region for $1\lesssim n < 2$, we find superconductivity with a remarkably high $T_c$ around $n=1.5$ (quarter filling). Also in the doped system, there is a close connection between the orbital freezing crossover and superconductivity.
