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arXiv · 2607.08476

The charge density fluctuations and the Shrinking Fermi Liquid scenario for strange metallicity in cuprates

Sergio Caprara·Sauri Bhattacharyya·Carlo Di Castro·Giovanni Mirarchi·Götz Seibold·Marco Grilli
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Abstract

We interpret the strange metal (SM) properties of slightly overdoped cuprates in terms of the recently proposed Shrinking Fermi Liquid theory. This is based on the pervading presence in the cuprate phase diagram of charge density fluctuations (CDF), which have been identified and characterized in RIXS. These fluctuations are abundant and have a low energy due to the proximity of the charge density wave quantum critical point hidden under the superconducting dome of cuprates, but have a short range and non-critical character with a finite energy M/\gamma ~10 meV as measured above Tc. Here M~ \xi^-2 is determined by the short correlation length \xi, while \gamma encodes the Landau damping ruling the lifetime of the charge fluctuations. Besides these low energy CDF, cuprates also display phonons and a broad continuum of particle-hole excitations, mostly due to spin paramagnons arising from their strongly correlated character. With these experimentally characterized ingredients we show that above Tc the SM properties in transport are well described in terms of fermionic Landau quasiparticles scattering with CDF and phonons. The optical properties can instead be interpreted by the combined effect of low energy CDF determining the temperature dependence, and of the paramagnon continuum determining a linear in frequency scattering rate. Remarkably, the combined effect of these simple ingredients also induces \omega/T scaling properties for frequencies larger than M/\gamma. When superconductivity is suppressed by strong magnetic fields the SM properties extend down to a few Kelvin. By assuming that the CDF dissipation parameter \gamma grows logarithmically by lowering T, we account for all anomalous transport and thermodynamic properties of cuprates (specific heat, Seebeck, heat transport, resistivity, and magnetoresistance) thereby providing a consistent scenario for the SM phase of cuprates.

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Sergio Caprara, Sauri Bhattacharyya, Carlo Di Castro, Giovanni Mirarchi, Götz Seibold, Marco Grilli. 2026-07-09. The charge density fluctuations and the Shrinking Fermi Liquid scenario for strange metallicity in cuprates. https://arxiv.org/abs/2607.08476

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