论文标题
Sr $ _2 $ ruo $ _4 $之间的旋转轨道耦合与范霍夫的奇异性之间的相互作用
Interplay between spin-orbit coupling and van Hove singularity in the Hund's metallicity of Sr$_2$RuO$_4$
论文作者
论文摘要
我们使用密度功能理论以及具有精确的对角度求解器的动态均值理论以及具有精确的对角度求解器的动力学理论，研究零$ _4 $的SR $ _2 $ ruo $ _4 $的动力学特性。通过考虑旋转不变的局部相互作用，我们检查了Hund的耦合和自旋轨道耦合如何影响系统的相关性质。在没有Hund的耦合的情况下，该系统在我们考虑的整个温度范围内显示出Fermi液体行为。我们确认即使在非零hund的耦合下，费米液体仍处于零温度下。但是，在足够的温度下，洪德的耦合会大大降低费米液体状态，系统将其演变成典型的洪德金属。在SR $ _2 $ ruo $ _4 $（$ t_ {2g}^4 $）的光占用时，较大的hund的金属性伴随着更大的长期相关器。值得注意的是，即使掺杂时的长期相关器和磁波动减少，电子兴奋剂的兴奋剂也进一步破坏了费米液体的稳定。对费米液体的这种抑制是由Sr $ _2 $ ruo $ _4 $的范霍夫奇异性驱动的，结合了增强的van vleck易感性，通过旋转轨道耦合。这样的发现表明，除了磁波动外，电子结构在Hund金属的行为中发挥了重要作用。
We investigate the dynamical properties of Sr$_2$RuO$_4$ at zero and very low temperature using density functional theory plus dynamical mean-field theory with an exact diagonalization solver. By considering rotationally invariant local interaction, we examine how Hund's coupling and spin-orbit coupling affect the correlated nature of the system. In the absence of Hund's coupling, the system shows a Fermi liquid behavior over the entire range of temperatures we consider. We confirm that the Fermi liquid persists at zero temperature even with nonzero Hund's coupling; however, at sufficient temperatures Hund's coupling significantly reduces the Fermi liquid regime and the system evolves into a typical Hund's metal. At the bare electronic occupancy of Sr$_2$RuO$_4$ ($t_{2g}^4$), a stronger Hund's metallicity accompanies a larger long-time correlator. Remarkably, electron doping further destabilizes the Fermi liquid even though the long-time correlator and magnetic fluctuations decrease upon doping. This suppression of the Fermi liquid is driven by the van Hove singularity above the Fermi level in Sr$_2$RuO$_4$, combined with an enhanced Van Vleck susceptibility by spin-orbit coupling. Such findings point to the important role that electronic structure plays in the behavior of Hund's metals, in addition to magnetic fluctuations.
