NMR and neutron scattering experiments. Indications for magnetic inhomogeneities in high-Tc cuprates

In this communication we consider the doping dependence of the strong antiferromagnetic fluctuations in the cuprate superconductors. We will show that nuclear magnetic resonance (NMR) and inelastic neutron scattering (INS) experiments can be described within a single theoretical scenario. We investigate the effect of an incommensurate magnetic response, as recently observed in INS experiments on several YBa2Cu3O6+x compounds, on the spin-lattice and spin-echo relaxation rates measured in NMR experiments. We conclude that a consistent theoretical description of INS and NMR can be reached if one assumes spatially inhomogeneous but locally commensurate spin correlations. We discuss a simple scenario of magnetic inhomogeneities which includes the main physical ingredients required to be consistent with experiments. (author)