Strongly Correlated Materials from a Numerical Renormalization Group Perspective: How the Fermi-Liquid State of Sr2RuO4 Emerges
Strongly Correlated Materials from a Numerical Renormalization Group Perspective: How the Fermi-Liquid State of Sr2RuO4 Emerges
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DOI：
10.1103/physrevlett.124.016401
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发表时间：
2020-01-02
影响因子：
8.6
通讯作者：
Georges, Antoine
中科院分区：
文献类型：
--
作者：
Kugler, Fabian B.;Zingl, Manuel;Georges, Antoine
当温度或能量降低时，从波动的原子成分到集体状态的交叉是固态的动力学平均场理论描述的核心。我们证明了数值重整化群是一个可行的工具来监测这种交叉在一个真实的材料设置。从高到任意小的能量尺度的重整化群流清楚地揭示了费米液态Sr2RuO4的出现。我们发现了一个两阶段的屏蔽过程，其中轨道波动屏蔽在更高的能量比自旋波动，费米液体的行为，伴随着自旋相干，低于25 K的温度。通过计算实频相关函数，我们直接观察到这种自旋轨道尺度分离，并表明货车霍韦奇异性驱动强轨道分化。我们从低能谱中提取准粒子相互作用参数，并在自旋三重态扇区中找到了有效的吸引力。
The crossover from fluctuating atomic constituents to a collective state as one lowers temperature or energy is at the heart of the dynamical mean-field theory description of the solid state. We demonstrate that the numerical renormalization group is a viable tool to monitor this crossover in a real-materials setting. The renormalization group flow from high to arbitrarily small energy scales clearly reveals the emergence of the Fermi-liquid state of Sr2RuO4. We find a two-stage screening process, where orbital fluctuations are screened at much higher energies than spin fluctuations, and Fermi-liquid behavior, concomitant with spin coherence, below a temperature of 25 K. By computing real-frequency correlation functions, we directly observe this spin-orbital scale separation and show that the van Hove singularity drives strong orbital differentiation. We extract quasiparticle interaction parameters from the low-energy spectrum and find an effective attraction in the spin-triplet sector.