Magnetic fluctuations and resonant peak in cuprates: a microscopic theory

摘要

The theory for the dynamical spin susceptibility within the t-J model isdeveloped, as relevant for the resonant magnetic peak and normal-state magneticresponse in superconducting (SC) cuprates. The analysis is based on theequations of motion for spins and the memory-function presentation of magneticresponse where the main damping of the low-energy spin collective mode comesfrom the decay into fermionic degrees of freedom. It is shown that the dampingfunction at low doping is closely related to the c-axis optical conductivity.The analysis reproduces doping-dependent features of the resonant magneticscattering.