Scaling of the magnetic response in doped antiferromagnets

TL;DR

This paper presents a theory explaining the anomalous omega/T scaling of magnetic response in doped cuprates, supported by exact diagonalization results and consistent with neutron scattering data.

Contribution

It introduces a novel theoretical framework based on the memory function approach to describe magnetic response scaling in doped antiferromagnets.

Findings

The damping of collective modes remains constant and large at low doping.

Spin correlations saturate at low temperatures.

The theory aligns well with experimental neutron scattering observations.

Abstract

A theory of the anomalous $\omega/T$ scaling of the dynamic magnetic response in cuprates at low doping is presented. It is based on the memory function representation of the dynamical spin suceptibility in a doped antiferromagnet where the damping of the collective mode is constant and large, whereas the equal-time spin correlations saturate at low $T$. Exact diagonalization results within the t-J model are shown to support assumptions. Consequences, both for the scaling function and the normalization amplitude, are well in agreement with neutron scattering results.