Gapped plasmon excitations and interlayer hopping in cuprate superconductors
ORAL
Abstract
Acoustic plasmons emerge in layered systems with conducting planes and poorly screened interlayer Coulomb interaction. Here, we use resonant inelastic x-ray scattering (RIXS) to probe the dispersion of plasmons in the electron-doped cuprate superconductor Sr0.9La0.1CuO2 (SLCO). We detect a plasmon gap of ∼120 meV at the two-dimensional Brillouin zone center, indicating that low-energy plasmons in SLCO are not strictly acoustic. Our t-J-V model calculations accurately capture the plasmon gap and establish that its size is directly related to the magnitude of the interlayer hopping tz—a parameter that is of key importance for realistic theories, yet notoriously difficult to assess with other techniques. Our work signifies the three-dimensionality of the charge dynamics in layered cuprates and provides a new method to determine tz.
*This work is supported by JSPS KAKENHI Grant No. JP20H01856 and the Air Force Office of Scientific Research through Grant No. FA9550-21-1-0168
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Publication: M. Hepting et al., Gapped collective charge excitations and interlayer hopping in cuprate superconductors, submitted
Presenters
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Matthias Hepting
- Max Planck Institute for Solid State Research
- Max Planck Institute for Solid State Phy