Properties of a classical spin liquid: the Heisenberg pyrochlore antiferromagnet

TL;DR

This paper investigates the classical Heisenberg antiferromagnet on the pyrochlore lattice, revealing persistent disorder and a temperature-dependent relaxation time due to geometrical frustration.

Contribution

It provides a detailed analysis combining theoretical fluctuation analysis and simulations to characterize the disordered nature of the spin liquid in this model.

Findings

System remains disordered at all temperatures

Relaxation time scales as 1/T at low temperatures

Ground state has extensive degeneracy due to frustration

Abstract

We study the low-temperature behaviour of the classical Heisenberg antiferromagnet with nearest neighbour interactions on the pyrochlore lattice. Because of geometrical frustration, the ground state of this model has an extensive number of degrees of freedom. We show, by analysing the effects of small fluctuations around the ground-state manifold, and from the results of Monte Carlo and molecular dynamics simulations, that the system is disordered at all temperatures, T, and has a finite relaxation time, which varies as 1/T for small T.