Off Equilibrium Study of the Fluctuation-Dissipation Relation in the Easy-Axis Heisenberg Antiferromagnet on the Kagome Lattice

TL;DR

This study investigates the violation of the fluctuation-dissipation theorem in a frustrated Kagome lattice Heisenberg antiferromagnet, revealing glassy behavior, slow dynamics, and FDT breakdown consistent with mean field spin glass theory.

Contribution

It provides the first evidence of a constant fluctuation dissipation ratio and long-range memory effects in this model, aligning with mean field predictions.

Findings

Glassy behavior and slow dynamics at low temperatures.

Constant fluctuation dissipation ratio observed.

FDT breakdown matches mean field spin glass theory.

Abstract

Violation of the fluctuation-dissipation theorem (FDT) in a frustrated Heisenberg model on the Kagome lattice is investigated using Monte Carlo simulations. The model exhibits glassy behaviour at low temperatures accompanied by very slow dynamics. Both the spin-spin autocorrelation function and the response to an external magnetic field are studied. Clear evidence of a constant value of the fluctuation dissipation ratio and long range memory effects are observed for the first time in this model. The breakdown of the FDT in the glassy phase follows the predictions of the mean field theory for spin glasses with one-step replica symmetry breaking.