• DOI:10.1038/s41535-019-0205-9
• Corpus ID: 195699731

Doping evolution of the charge excitations and electron correlations in electron-doped superconducting La2−xCexCuO4

@article{Lin2020DopingEO,
  title={Doping evolution of the charge excitations and electron correlations in electron-doped superconducting La2−xCexCuO4},
  author={Jiaqi Lin and Jie Yuan and Kuijuan Jin and Zhiping Yin and Gang Li and K. J. Zhou and Xingye Lu and Marcus Dantz and Thorsten Schmitt and Hong Ding and Haizhong Guo and Mark. P. M. Dean and Xuerong Liu},
  journal={npj Quantum Materials},
  year={2020}
}

• Jiaqi Lin, Jie Yuan, +10 authors Xuerong Liu
• Published 27 June 2019
• Physics
• npj Quantum Materials

Electron correlations play a dominant role in the charge dynamics of the cuprates. We use resonant inelastic X-ray scattering (RIXS) to track the doping dependence of the collective charge excitations in electron doped La$${}_{2-x}$$

2
−
x

Ce$${}_{x}$$

x

CuO$${}_{4}$$

4

(LCCO). From the resonant energy dependence and the out-of-plane momentum dependence, the charge excitations are identified as three-dimensional (3D) plasmons, which reflect the nature of the electronic structure and Coulomb repulsion on both short and long lengthscales. With increasing electron doping, the plasmon excitations increase monotonically in energy, a consequence of the electron correlation effect on electron structure near the Fermi surface (FS). Importantly, the plasmon excitations evolve from a broad feature into a well-defined peak with much increased life time, revealing the evolution of the electrons from incoherent states to coherent quasi-particles near the FS. Such evolution marks the reduction of the short-range electronic correlation, and thus the softening of the Mottness of the system with increasing electron doping.