engleski

Universal sheet resistance of the cuprate superconductors

Upon introducing charge carriers into the underlying copper-oxygen sheets of the cuprates, the parent insulator evolves into a superconductor and eventually into a seemingly conventional Fermi liquid. Much has remained elusive about the nature of this evolution, and about the peculiar metallic state at intermediate hole-carrier concentrations (p), where the planar resistivity exhibits a linear temperature dependence (ρT) that is disrupted upon cooling toward the superconducting state by the opening of a `pseudogap' along the Fermi surface. Here we demonstrate for the quintessential compound HgBa2CuO4+δ a purely Fermi-liquid-like resistivity (ρT^2) deep in the pseudogap regime. Our result when combined with select prior work for other compounds reveals the fundamental resistance per copper-oxygen sheet in both the linear (ρS=A1ST) and quadratic (ρS=A2ST^2) regimes, with A1S A2S 1/p. Theoretical models for the cuprates can now be benchmarked against this remarkably simple universal behavior. Preprint: arXiv:1207.1504. Work supported by DOE-BES.

sheet resistance; cuprate superconductors

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