Magnetic fluctuations and resonant peak in cuprates: a microscopic theory

TL;DR

This paper develops a microscopic theory for magnetic fluctuations in cuprates, explaining the resonant peak and magnetic response in superconducting states through the t-J model and spin-fermion interactions.

Contribution

It introduces a detailed microscopic framework for understanding magnetic excitations and damping in cuprates, linking spin dynamics to optical conductivity.

Findings

Reproduces doping-dependent resonant magnetic scattering features

Connects low-energy spin damping to c-axis optical conductivity

Provides a microscopic basis for magnetic response in cuprates

Abstract

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