NMR evidence for spatial modulations in the cuprates

Nuclear magnetic resonance (NMR) data on Cu, apical and planar O in La1.85S r0.15CuO4 are presented. Spin echo double resonance shows that the large Cu magnetic shift distribution is of short-length scale. Analysis of the O da ta reveals static modulations of the spin susceptibility with a spin-spin c orrelation function near zero. The Cu shift distribution is found to be of orbital origin. The full planar oxygen spectra show a correlated modulation of the electric field gradient with the spin susceptibility. Similar resul ts on other cuprates indicate universality of these phenomena.