Charge order and its connection with Fermi-liquid charge transport in a pristine high-Tc cuprate

Electronic inhomogeneity appears to be an inherent characteristic of the enigmatic cuprate superconductors. Here we report the observation of charge–density–wave correlations in the model cuprate superconductor HgBa 2 CuO 4+ δ ( T c =72 K) via bulk Cu L 3 -edge-resonant X-ray scattering. At the measured hole-doping level, both the short-range charge modulations and Fermi-liquid transport appear below the same temperature of about 200 K. Our result points to a unifying picture in which these two phenomena are preceded at the higher pseudogap temperature by q =0 magnetic order and the build-up of significant dynamic antiferromagnetic correlations. The magnitude of the charge modulation wave vector is consistent with the size of the electron pocket implied by quantum oscillation and Hall effect measurements for HgBa 2 CuO 4+ δ and with corresponding results for YBa 2 Cu 3 O 6+ δ , which indicates that charge–density–wave correlations are universally responsible for the low-temperature quantum oscillation phenomenon. Charge–density–wave correlations, quantum oscillations and Fermi-liquid charge transport are at the centre of a heated debate in cuprate superconductivity. Using resonant X-ray scattering, Tabis et al. investigate the charge order and its link to the electronic transport properties in HgBa 2 CuO 4+ δ .