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Universality of the single-particle spectra of cuprate superconductors

Lijun Zhu·Vivek Aji·Arkady Shekhter·C. M. Varma
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Abstract

All the available data for the dispersion and linewidth of the single-particle spectra above the superconducting gap and the pseudogap in metallic cuprates for any doping has universal features. The linewidth is linear in energy below a scale $ω_c$ and constant above. The cusp in the linewidth at $ω_c$ mandates, due to causality, a "waterfall", i.e., a vertical feature in the dispersion. These features are predicted by a recent microscopic theory. We find that all data can be quantitatively fitted by the theory with a coupling constant $λ_0$ and an upper cutoff at $ω_c$ which vary by less than 50% among the different cuprates and for varying dopings. The microscopic theory also gives these values to within factors of O(2).

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Lijun Zhu, Vivek Aji, Arkady Shekhter, C. M. Varma. 2008-01-09. Universality of the single-particle spectra of cuprate superconductors. https://doi.org/10.1103/physrevlett.100.057001

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