Spin Dynamics in the Normal State of High T_c Superconductors

TL;DR

This paper reviews theoretical insights into the spin dynamics of normal-state high-temperature cuprate superconductors, emphasizing the role of fermiology and correlations in explaining experimental observations.

Contribution

It provides a theoretical framework linking spin dynamics to fermiology and Coulomb correlations, explaining experimental anomalies in cuprates.

Findings

Different wave vector dependencies in LaSrCuO and YBaCuO explained by fermiology.

Temperature and frequency dependence of spin structure factor accounted for by correlations.

Low energy spin dynamics described by correlated quasiparticles with a Luttinger Fermi surface.

Abstract

We summarize our recent theoretical studies on the spin dynamics in the normal state of the metallic cuprates. The contrasting wave vector dependence of the dynamical spin structure factor $S({\bf q}, \omega )$ in LaSrCuO and YBaCuO systems are attributed to the differences in the fermiology, in conjunction with strong Coulomb correlations. These effects are found to account also for the anomalous temperature and frequency dependence of $S({\bf q}, \omega )$. We conclude that the low energy spin dynamics of the metallic cuprates are described in terms of correlated quasiparticles with a Luttinger Fermi surface and a non-zero antiferromagnetic exchange interaction.