论文标题
二维Hubbard模型中假单和自旋旋转相关性的掺杂和温度演变
Doping and temperature evolution of pseudogap and spin-spin correlations in the two-dimensional Hubbard model
论文作者
论文摘要
群集扰动理论应用于二维Hubbard $ t-t'-t'' - U $模型，以获得掺杂和温度相关的电子光谱函数，$ 4 \ times times timple 4 $和12个地点簇。结果表明，伪gap的演变和掺杂和温度的电子散布的演变相似，在这两种情况下，它都受到自旋旋转短距离相关性的显着影响。当短距离磁性顺序通过掺杂或温度而削弱，而Hubbard-i则像电子色散变得更加明显时，费米弧变成了大型费米表面，伪gap关闭。这证明了静态自旋相关性如何影响整体分散体的形状，以及动态贡献的考虑如何导致费米表面的动量依赖频谱体重和扩大效果。
Cluster perturbation theory is applied to the two-dimensional Hubbard $t-t'-t''-U$ model to obtain doping and temperature dependent electronic spectral function with $4 \times 4$ and 12-site clusters. It is shown that evolution of the pseudogap and electronic dispersion with doping and temperature is similar and in both cases it is significantly influenced by spin-spin short-range correlations. When short-range magnetic order is weakened by doping or temperature and Hubbard-I like electronic dispersion becomes more pronounced, the Fermi arc turns into large Fermi surface and the pseudogap closes. It is demonstrated how static spin correlations impact the overall dispersion's shape and how accounting for dynamic contributions leads to momentum-dependent spectral weight at the Fermi surface and broadening effects.
