Mousatov Connie H, Berg Erez, Hartnoll Sean A
Department of Physics, Stanford University, Stanford, CA 94305.
Department of Condensed Matter Physics, The Weizmann Institute of Science, Rehovot 76100, Israel;
Proc Natl Acad Sci U S A. 2020 Feb 11;117(6):2852-2857. doi: 10.1073/pnas.1915224117. Epub 2020 Jan 24.
The bilayer perovskite SrRuO has been widely studied as a canonical strange metal. It exhibits -linear resistivity and a log(1/) electronic specific heat in a field-tuned quantum critical fan. Criticality is known to occur in "hot" Fermi pockets with a high density of states close to the Fermi energy. We show that while these hot pockets occupy a small fraction of the Brillouin zone, they are responsible for the anomalous transport and thermodynamics of the material. Specifically, a scattering process in which two electrons from the large, "cold" Fermi surfaces scatter into one hot and one cold electron renders the ostensibly noncritical cold fermions a marginal Fermi liquid. From this fact the transport and thermodynamic phase diagram is reproduced in detail. Finally, we show that the same scattering mechanism into hot electrons that are instead localized near a 2D van Hove singularity explains the anomalous transport observed in strained SrRuO.
双层钙钛矿SrRuO作为一种典型的奇异金属已被广泛研究。在磁场调谐量子临界扇区中，它表现出线性电阻率和对数(1/T)电子比热。已知临界性发生在“热”费米面口袋中，这些口袋在费米能量附近具有高密度的态。我们表明，虽然这些热口袋仅占据布里渊区的一小部分，但它们却导致了该材料异常的输运和热力学性质。具体而言，一个散射过程，即来自大的“冷”费米面的两个电子散射成一个热电子和一个冷电子，使得表面上非临界的冷费米子成为边缘费米液体。基于这一事实，详细再现了输运和热力学相图。最后，我们表明，同样的散射机制进入到二维范霍夫奇点附近局域化的热电子中，解释了在应变SrRuO中观察到的异常输运现象。
