Low-frequency incommensurate magnetic response in strongly correlated systems

TL;DR

This paper demonstrates that the t-J model predicts low-frequency incommensurate magnetic peaks in cuprate planes, aligning with experimental observations and showing dependence on doping levels and temperature.

Contribution

It provides a theoretical explanation for incommensurate magnetic responses in strongly correlated systems using the t-J model, linking it to experimental data.

Findings

Incommensurate peaks occur at specific wave vectors in the t-J model.

Incommensurability delta is proportional to doping level x for 0.02<x<=0.12.

Incommensurability diminishes with increasing temperature.

Abstract

It is shown that in the t-J model of Cu-O planes at low frequencies the dynamic spin structure factor is peaked at incommensurate wave vectors (1/2+-delta,1/2)$, (1/2,1/2+-delta). The incommensurability is connected with the momentum dependencies of the magnon frequency and damping near the antiferromagnetic wave vector. The behavior of the incommensurate peaks is similar to that observed in La_{2-x}(Ba,Sr)_xCuO_{4+y} and YBa_2Cu_3O_{7-y}: for hole concentrations 0.02<x<=0.12 we find that delta is nearly proportional to x, while for x>0.12 it tends to saturation. The incommensurability disappears with increasing temperature. Generally the incommensurate magnetic response is not accompanied by an inhomogeneity of the carrier density.