Charge ordering and Fermi-arc instability in underdoped cuprates

The underdoped cuprate pseudogap, and related ``Fermi-arc'' phenomenology, is one of the most remarkable phenomena in strongly correlated-electron systems. Despite evidence for various forms of electronic instabilities, a direct link to an underlying ordered phase is still mysterious. Here we report a combined investigation of one single cuprate family by real- and momentum-space, and surface and bulk probes - resonant X-ray scattering (REXS), scanning-tunnelling microscopy (STM), and angle-resolved photoemission spectroscopy (ARPES)--which individually had a profound impact on the understanding of high-Tc cuprate superconductors, but have so-far been analyzed and interpreted within different phenomenological frameworks--and never for the very same compound. By bringing together these techniques, and with the aid of calculations of the electronic response, we establish a precise, quantitative correspondence between the Fermi arc phenomenon seen in ARPES and charge ordering as observed by REXS and STM. These converging findings suggest the existence of a universal charge-ordered state in underdoped cuprates and reveal its connection to the pseudogap phase and related fermiology.