Charge order correlations in Bi-based high-temperature cuprate superconductors measured by resonant x-ray scattering.

We use resonant x-ray scattering to measure the doping dependence of the charge order (or charge density wave) in the BSCCO 2212 high-temperature superconductor. We detect the charge order in the underdoped regime (between 0.07 hole doping and optimal doping). We also find that the charge order wave vector is doping dependent spanning Q$=$0.25 to Q$=$0.29, following inter-pocket scattering. Furthermore, our bulk sensitive results show an equivalence to the charge order previously measured on the surface of BSCCO 2212 by scanning tunneling spectroscopy [E. H. da Silva Neto, et al. Science 343, 393 (2014)].