Local Magnetic Order vs Superconductivity in a Layered Cuprate

We report on the phase diagram for charge-stripe order in ${\mathrm{La}}_{1.6-x}{\mathrm{Nd}}_{0.4}{\mathrm{Sr}}_x{\mathrm{CuO}}_4$, determined by neutron and x-ray scattering studies and resistivity measurements. From an analysis of the in-plane resistivity motivated by recent nuclear-quadrupole-resonance studies, we conclude that the transition temperature for local charge ordering decreases monotonically with $x$, and hence that local antiferromagnetic order is uniquely correlated with the anomalous depression of superconductivity at $x\approx \frac{1}{8}$. This result is consistent with theories in which superconductivity depends on the existence of charge-stripe correlations.