Impact of electron correlations on two-particle charge response in electron- and hole-doped cuprates

Abstract

Estimating many-body effects that deviate from an independent particle approach, has long been a key research interest in condensed matter physics. Layered cuprates are prototypical systems, where electron-electron interactions are found to strongly affect the dynamics of single-particle excitations. It is however, still unclear how the electron correlations influence charge excitations, such as plasmons, which have been variously treated with either weak or strong correlation models. In this work, we demonstrate the hybridised nature of collective valence charge fluctuations leading to dispersing acoustic-like plasmons in hole-doped La${}_{1.84}$Sr${}_{0.16}$CuO${}_4$ and electron-doped La${}_{1.84}$Ce${}_{0.16}$CuO${}_4$ using the two-particle probe, resonant inelastic x-ray scattering. We then describe the plasmon dispersions in both systems, within both the weak mean-field Random Phase Approximation (RPA) and strong coupling $t$-$J$-$V$ models. The $t$-$J$-$V$ model, which includes the correlation effects implicitly, accurately describes the plasmon dispersions as resonant excitations outside the single-particle intra-band continuum. In comparison, a quantitative description of the plasmon dispersion in the RPA approach is obtained only upon explicit consideration of re-normalized electronic band parameters. Our comparative analysis shows that electron correlations significantly impact the low-energy plasmon excitations across the cuprate doping phase diagram, even at long wavelengths. Thus, complementary information on the evolution of electron correlations, influenced by the rich electronic phases in condensed matter systems, can be extracted through the study of two-particle charge response.

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References in corpus (19)

• Emergent complex neural dynamics
• How bad metals turn good: spectroscopic signatures of resilient quasiparticles
• Universal scaling of the critical temperature and the strange-metal scattering rate in unconventional superconductors
• Effect of strong correlations on the high energy anomaly in hole- and electron-doped high-Tc superconductors
• Collective Charge Excitations of Strongly Correlated Electrons, Vertex Corrections and Gauge Invariance
• Correlation Strength, Gaps and Particle-Hole Asymmetry in High-Tc Cuprates: a Dynamical Mean Field Study of the Three-Band Copper-Oxide Model
• Reconciling scaling of the optical conductivity of cuprate superconductors with Planckian resistivity and specific heat
• Doping dependence of the magnetic excitations in La${}_{2-x}$Sr${}_x$CuO${}_4$
• Superconductivity in high-$T_c$ and related strongly correlated systems from variational perspective: Beyond mean field theory
• The impact of dynamical screening on the phonon dynamics of LaCuO
• Gapped collective charge excitations and interlayer hopping in cuprate superconductors
• Evolution of plasmon excitations across the phase diagram of the cuprate superconductor La${}_{2-x}$Sr${}_x$CuO${}_4$
• A unified theory of spin and charge excitations in high-$T_c$ cuprates: Quantitative comparison with experiment and interpretation
• Dual structure in the charge excitation spectrum of electron-doped cuprates
• The fate of quasiparticles at high-temperature
• Plasmon dispersion in bilayer cuprate superconductors
• Propagating charge carrier plasmon in Sr2RuO4
• Plasmarons in high-temperature cuprate superconductors
• Spin and bond-charge excitation spectra in correlated electron systems near antiferromagnetic phase

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