Three-Dimensional Fermi Surface of Overdoped La-Based Cuprates
Three-Dimensional Fermi Surface of Overdoped La-Based Cuprates
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DOI：
10.1103/physrevlett.121.077004
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发表时间：
2018-08-17
影响因子：
8.6
通讯作者：
Chang, J.
中科院分区：
文献类型：
--
作者：
Horio, M.;Hauser, K.;Chang, J.
我们提出了超掺杂高温超导体的软x射线角分辨光发射光谱研究。通过改变光发射角度和入射光子能量来映射费米面的面内和面外分量。没有k(z)色散观察到沿节点方向，而一个显著的反节点的k(z)色散被确定为la基铜酸盐。基于紧约束参数化，我们讨论了在van Hove奇点附近态密度的影响。我们的结果表明，La2-xSrxCuO4中发现的大电子比热不能单独归因于van Hove奇点。因此，我们提出由赝隙相坍缩引起的量子临界性作为观察到的电子比热增强的合理解释。
We present a soft x-ray angle-resolved photoemission spectroscopy study of overdoped high-temperature superconductors. In-plane and out-of-plane components of the Fermi surface are mapped by varying the photoemission angle and the incident photon energy. No k(z) dispersion is observed along the nodal direction, whereas a significant antinodal k(z) dispersion is identified for La-based cuprates. Based on a tight-binding parametrization, we discuss the implications for the density of states near the van Hove singularity. Our results suggest that the large electronic specific heat found in overdoped La2-xSrxCuO4 cannot be assigned to the van Hove singularity alone. We therefore propose quantum criticality induced by a collapsing pseudogap phase as a plausible explanation for observed enhancement of electronic specific heat.