Breakdown of the universal Josephson relation in spin-ordered cuprate superconductors

We present c-axis infrared optical data on a number of Ba-, Sr-, and Nd-doped cuprates of the La2CuO4 (La214) series in which we observe significant deviations from the universal Josephson relation linking the normal-state transport (dc conductivity sigma(dc) measured at T-c) with the superfluid density (rho(s)): rho(s) proportional to sigma(dc)(T-c). We find the violation of Josephson scaling is associated with striking enhancement of the anisotropy in the superfluid density. The data allow us to link the breakdown of Josephson interlayer physics with the development of magnetic order in the CuO2 planes.