论文标题
方形扩展哈伯德模型的超导阶段
Superconducting Phases of the Square-Lattice Extended Hubbard Model
论文作者
论文摘要
我们通过现场$ U $和最近的邻居$ v $互动来研究Square-Lattice扩展的Hubbard模型。我们表明，非平衡淬灭动力学可以帮助确定平衡相变边界，这与富达度量，动力学结构因子和相关函数的计算一致。在半填充时，强耦合体制中的相图包括旋转密度波和$ d_ {x^^2-y^2} $ - 在很大的正$ u $上，电荷密度波（扩展$ s^*$ - 波动超导率）在大型正面（负面）$ v $，以及$ s $ s $ s $ -wave upercondivity and $ s $ - $ s $ $ u $ $ u $ $ u $ $ u $。不同粒子部门的能量还有助于确定相分离区域。通过载体掺杂，电荷波动会导致不同订单之间的强烈竞争，从而使确定有限尺寸群集的领先不稳定变得更加困难。然而，当系统大量超过$ 37.5 \％-50 \％$孔时，发现更异国情调的$ p $ - 波超导配对将得到增强，尤其是在与乡土超级导体相关的交互参数范围内。
We study the square-lattice extended Hubbard model with on-site $U$ and nearest-neighbor $V$ interactions by exact diagonalization. We show that non-equilibrium quench dynamics can help determine the equilibrium phase transition boundaries, which agree with the calculations of fidelity metric, dynamical structure factor, and correlation function. At half filling, the phase diagrams in the strong-coupling regime include spin density wave and $d_{x^2-y^2}$-wave superconductivity at large positive $U$, charge density wave (extended $s^*$-wave superconductivity) at large positive (negative) $V$, and $s$-wave superconductivity at large negative $U$ with vanishing $V$. The energies of different particle sectors also help determine the phase separation region. With carrier doping, charge fluctuation result in strong competition between different orders, making it more difficult to identify the leading instability on finite-size cluster. Nevertheless, the more exotic $p$-wave superconducting pairing is found to be enhanced when the system is heavily overdoped by $37.5\%-50\%$ holes, especially in interaction parameter range relevant to the cuprate superconductors.
