Inhomogeneous Charge State in HTSC Cuprates and CMR Manganites

Recent measurements of neutron elastic and inelastic scattering suggest that the charge states are spatially inhomogeneous at two lengthscales, atomic and nanometer scales, in both the high-temperature superconducting (HTSC) cuprates and colossal magnetoresistive (CMR) manganites. We suggest that the two-phonon mechanism that controls the charge localization in CMR manganites is also at work in HTSC cuprates, and may hold a key to understanding the mechanism of superconductivity.