Evolution of plasmon excitations across the phase diagram of the cuprate superconductor La${}_{2-x}$Sr${}_x$CuO${}_4$

Abstract

We use resonant inelastic x-ray scattering (RIXS) at the O $K$- and Cu $K$-edges to investigate the doping- and temperature dependence of low-energy plasmon excitations in La${}_{2-x}$Sr${}_x$CuO${}_4$. We observe a monotonic increase of the energy scale of the plasmons with increasing doping $x$ in the underdoped regime, whereas a saturation occurs above optimal doping $x\gtrsim 0.16$ and persists at least up to $x=0.4$. Furthermore, we find that the plasmon excitations show only a marginal temperature dependence, and possible effects due to the superconducting transition and the onset of strange metal behavior are either absent or below the detection limit of our experiment. Taking into account the strongly correlated character of the cuprates, we show that layered $t$-$J$-$V$ model calculations accurately capture the increase of the plasmon energy in the underdoped regime. However, the computed plasmon energy continues to increase even for doping levels above $x\gtrsim 0.16$, which is distinct from the experimentally observed saturation, and reaches a broad maximum around $x=0.55$. We discuss whether possible lattice disorder in overdoped samples, a renormalization of the electronic correlation strength at high dopings, or an increasing relevance of non-planar Cu and O orbitals could be responsible for the discrepancy between experiment and theory for doping levels above $x=0.16$.

19 pages, 11 figures

References in corpus (23)

• Linear in Temperature Resistivity and Associated Mysteries
• Two-Orbital Model Explains the Higher Transition Temperature of the Single-Layer Hg-Cuprate Superconductor Compared to That of the La-Cuprate Superconductor
• Planckian Dissipation in Metals
• Momentum Dependence of Charge Excitations in the Electron-Doped Superconductor Nd1.85Ce0.15CuO4: a RIXS Study
• Detection of Acoustic Plasmons in Hole-Doped Lanthanum and Bismuth Cuprate Superconductors Using Resonant Inelastic X-Ray Scattering
• The dynamics of a doped hole in cuprates is not controlled by spin fluctuations
• Acoustic plasmons and conducting carriers in hole-doped cuprate superconductors
• Violation of the isotropic-$\ell$ approximation in overdoped La_{2-x}Sr_xCuO_4
• Mott gap excitations in twin-free YBa2Cu3O7-d (Tc = 93 K) studied by RIXS
• The impact of dynamical screening on the phonon dynamics of LaCuO
• Gapped collective charge excitations and interlayer hopping in cuprate superconductors
• Band Structure of Overdoped Cuprate Superconductors: Density Functional Theory Matching Experiments
• Selective formation of apical oxygen vacancies in La${}_{2-x}$Sr${}_x$CuO${}_4$
• Generalized plasma waves in layered superconductors
• Close inspection of plasmon excitations in cuprate superconductors
• Anisotropic scattering caused by apical oxygen vacancies in thin films of overdoped high-temperature cuprate superconductors
• A unified theory of spin and charge excitations in high-$T_c$ cuprates: Quantitative comparison with experiment and interpretation
• Effect of realistic out-of-plane dopant potentials on the superfluid density of overdoped cuprates
• Charge Excitations in Nd${}_{2-x}$Ce${}_x$CuO${}_4$ Observed with Resonant Inelastic X-ray Scattering: Comparison of Cu K-edge with Cu L${}_3$-edge
• Probing the bulk plasmon continuum of layered materials through electron energy loss spectroscopy in a reflection geometry
• Low-energy plasmon excitations in infinite-layer nickelates
• Comment on: Crossover of Charge Fluctuations across the Strange Metal Phase Diagram
• Reply to arXiv:2103.10268 `Comment on "Crossover of Charge Fluctuations across the Strange Metal Phase Diagram'''

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