Dynamical Magnetic Susceptibility for the $t$-$J$ Model

TL;DR

This paper calculates the dynamical magnetic susceptibility of the $t$-$J$ model using dynamical mean field theory, revealing how ferromagnetic and antiferromagnetic interactions influence spin dynamics.

Contribution

It provides the first detailed dynamical susceptibility results for the $t$-$J$ model, highlighting the effects of exchange interactions on spin correlations.

Findings

Enhanced ferromagnetic correlations at J=0

Relatively q-independent susceptibility at J=0

Peak at antiferromagnetic Bragg point for J>0

Abstract

We present results for the {\em dynamical}\/ magnetic susceptibility of the $t$-$J$ model, calculated with the dynamical mean field theory. For $J=0$ we find enhanced ferromagnetic correlations but an otherwise relatively $\vec{q}$-independent dynamical magnetic susceptibility. For $J>0$ the explicit antiferromagnetic exchange leads to a dynamic spin structure factor with the expected peak at the antiferromagnetic Bragg point.