Nanoscale One-Dimensional Scattering Resonances in the CuO Chains ofYBa2Cu3O6+x

We present scanning tunneling spectroscopy measurements of the CuO chain plane in ${{\mathrm{YBa}}_2{\mathrm{Cu}}_3\mathrm{O}}_{6+x}$, showing a $\sim 25\mathrm{meV}$ gap in the local density of states (LDOS) filled by numerous intragap resonances: intense peaks in LDOS spectra associated with one-dimensional, Friedel-like oscillations. We discuss how these phenomena shed light on recent results from other probes, as well as their implications for phenomena in the superconducting ${\mathrm{CuO}}_2$ plane.