Numerical evidence for unstable magnons at high fields in the Heisenberg antiferromagnet on the square lattice

TL;DR

This paper provides numerical evidence that magnons become unstable and decay at high magnetic fields in the square lattice spin-1/2 Heisenberg antiferromagnet, using advanced simulation and inference techniques.

Contribution

It introduces a combined Quantum Monte Carlo and Bayesian inference approach to study magnon stability at high fields, confirming theoretical predictions.

Findings

Magnons decay at strong magnetic fields.

Results align with spin wave theory predictions.

Demonstrates effectiveness of Bayesian inference in quantum dynamics.

Abstract

We find evidence for decaying magnons at strong magnetic field in the square lattice spin-1/2 Heisenberg antiferromagnet. The results are obtained using Quantum Monte Carlo simulations combined with a Bayesian inference technique to obtain dynamics and are consistent with predictions from spin wave theory.