Linear Response Theory and the Universal Nature of the Magnetic Excitation Spectrum of the Cuprates

TL;DR

This paper uses linear response theory to predict a universal magnetic excitation spectrum in cuprate superconductors, comparing theoretical results with experimental neutron scattering data across different compounds and phases.

Contribution

It demonstrates that RPA calculations based on photoemission data can explain universal features of magnetic excitations in cuprates.

Findings

RPA predicts a universal magnetic excitation spectrum in cuprates.

Theoretical predictions align with neutron scattering data across multiple compounds.

Universality persists in both superconducting and non-superconducting phases.

Abstract

Linear response theory, commonly known as the random phase approximation (RPA), predicts a rich magnetic excitation spectrum for d-wave superconductors. Many of the features predicted by such calculations appear to be reflected in inelastic neutron scattering data of the cuprates. In this article, I will present results from RPA calculations whose input is based on angle resolved photoemission data, and discuss possible relevance to inelastic neutron scattering data of LSCO, YBCO, and Bi2212 in their superconducting and non-superconducting phases. In particular, the question of the universality of the magnetic excitation spectrum will be addressed.