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

Lin, Jiaqi; Yuan, Jie; Jin, Kui; Yin, Zhiping; Li, Gang; Zhou, Ke-Jin; Lu, Xingye; Dantz, Marcus; Schmitt, Thorsten; Ding, Hong; Guo, Haizhong; Dean, Mark P.  M.; Liu, Xuerong

doi:10.1038/s41535-019-0205-9

Title: Doping evolution of the charge excitations and electron correlations in electron-doped superconducting La_2-xCe_xCuO₄

Journal Article · 16 January 2020 · npj Quantum Materials

DOI: https://doi.org/10.1038/s41535-019-0205-9 · OSTI ID:1603280

^[1]; Yuan, Jie ^[1];

^[1]; Yin, Zhiping ^[1];

^[1];

^[1]; Lu, Xingye ^[1]; Dantz, Marcus ^[1]; Schmitt, Thorsten ^[1]; Ding, Hong ^[1];

^[1];

^[1]; Liu, Xuerong ^[1]

Brookhaven National Lab. (BNL), Upton, NY (United States)

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-xCe_xCuO₄ (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.

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Research Organization:: Brookhaven National Laboratory (BNL), Upton, NY (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)

Grant/Contract Number:: SC0012704

OSTI ID:: 1603280

Report Number(s):: BNL--213651-2020-JAAM

Journal Information:: npj Quantum Materials, Journal Name: npj Quantum Materials Journal Issue: 1 Vol. 5; ISSN 2397-4648

Publisher:: Nature Publishing GroupCopyright Statement

Country of Publication:: United States

Language:: English

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Title: Doping evolution of the charge excitations and electron correlations in electron-doped superconducting La_2-xCe_xCuO₄