Observation of correlated plasmons in low-valence nickelates

Abstract

The discovery of nickelate superconductors has opened a new arena for studying the behavior of correlated electron liquids that give rise to unconventional superconductivity. While critical information about a material's charge dynamics is encoded in its plasmons, collective modes of the electron gas, these excitations have not yet been observed in nickelate materials. Here, we use resonant inelastic x-ray scattering (RIXS) to detect plasmons in the metallic, low-valence nickelate Pr4Ni3O8. Although qualitatively similar to those in cuprates, the nickelate plasmons are more heavily damped and have a lower velocity than those in a cuprate at comparable doping, which we attribute to reduced electronic hopping and enhanced screening of the long-range Coulomb interactions. Furthermore, the plasmons in Pr4Ni3O8 soften with increasing temperature, in contrast to the cuprate, where plasmons remain at nearly fixed energy but become more strongly damped. Taken together, these results reveal a distinct charge-screening landscape in nickelates and place quantitative constraints on analogies to cuprates.

To appear in Physical Review X 6 pages plus references, appendices, and supplements

References in corpus (30)

• Superconductivity near 80 Kelvin in single crystals of La3Ni2O7 under pressure
• Superconductivity in pressurized trilayer La${}_4$Ni${}_3$O${}_{10-\delta }$ single crystals
• Ambient-pressure superconductivity onset above 40 K in bilayer nickelate ultrathin films
• Anomalously Strong Near-Neighbor Attraction in Doped 1D Cuprate Chains
• Character of the "normal state" of the nickelate superconductors
• Spin excitations in a single La${}_2$CuO${}_4$ layer
• Detection of Acoustic Plasmons in Hole-Doped Lanthanum and Bismuth Cuprate Superconductors Using Resonant Inelastic X-Ray Scattering
• Strong Superexchange in a $d^{9-\delta }$ Nickelate Revealed by Resonant Inelastic X-Ray Scattering
• Spin stripe order in a square planar trilayer nickelate
• Comparative Many-Body Study of Pr${}_4$Ni${}_3$O${}_8$ and NdNiO${}_2$
• Doping dependence of the magnetic excitations in La${}_{2-x}$Sr${}_x$CuO${}_4$
• Acoustic plasmons and conducting carriers in hole-doped cuprate superconductors
• Theoretical investigation of superconductivity in trilayer square-planar nickelates
• Exploring Quantum Materials with Resonant Inelastic X-Ray Scattering
• Review on quasi-2D square planar nickelates
• Short-range magnetic interactions and spin-glass behavior in the quasi-2D nickelate Pr4Ni3O8
• Gapped collective charge excitations and interlayer hopping in cuprate superconductors
• Enhancing $d$-wave superconductivity with nearest-neighbor attraction of extended Hubbard model
• Evolution of plasmon excitations across the phase diagram of the cuprate superconductor La${}_{2-x}$Sr${}_x$CuO${}_4$
• Role of Oxygen States in the Low Valence Nickelate La${}_4$Ni${}_3$O${}_8$
• Plasmon dispersion in bilayer cuprate superconductors
• Electronic character of charge order in square planar low valence nickelates
• Impact of electron correlations on two-particle charge response in electron- and hole-doped cuprates
• Theory of charge dynamics in bilayer electron system with long-range Coulomb interaction
• Beyond-Hubbard pairing in a cuprate ladder
• Low-energy plasmon excitations in infinite-layer nickelates
• Ghost Josephson plasmon in bilayer superconductors
• Out-of-phase Plasmon Excitations in the Trilayer Cuprate Bi${}_2$Sr${}_2$Ca${}_2$Cu${}_3$O${}_{10+\delta }$
• Orbital polarization, charge transfer, and fluorescence in reduced valence nickelates
• Resonant inelastic x-ray scattering data for Ruddlesden-Popper and reduced Ruddlesden-Popper nickelates