VI-3　Phonons and Magnetic Excitations of Y123 High Temperature Superconductors

Abstract

A brief overview is presented how neutron inelastic scattering method has been applied to the study on Cu oxide high-T_c superconductors. Here, we mainly show results of the measurements carried out on the YBa₂Cu₃O_6+x (Y123 system), and demonstrate how these works have presented meaningful information to identify the origin of the superconductivity and underlying unusual dynamical behaviors related to its active magnetism, which originates from the fact that the system is induced from the Mott-insulating state by doping holes (or electrons).