Flux roughening in spin ice with mixed $\pm J$ interactions

TL;DR

This paper studies how magnetic charge disorder affects flux roughening in 2D spin ice, revealing a transition from pinch points to diffusive peaks in the spin structure factor through novel algorithms and analytical relations.

Contribution

It introduces a new cluster update algorithm for efficient simulation and derives an analytical relation linking flux fluctuations to the spin structure factor.

Findings

Pinch point features are replaced by diffusive peaks with charge doping.

Flux roughening explains the evolution of the spin structure factor.

Efficient Monte Carlo method enables detailed analysis of flux behavior.

Abstract

Spin ice presents a typical example of classical spin liquid, where conserved magnetic fluxes emerge from microscopic spin degrees of freedom. In this letter, we investigate the effect of perturbation by magnetic charge disorder in two-dimensional spin ice. To this aim, we develop a novel cluster update algorithm, which enables fast relaxation of magnetic charges. The efficient Monte Carlo calculation reveals a drastic change of spin structure factor as doping magnetic charges: the pinch point, characterizing the spin ice, is gradually replaced by a diffusive peak. We derive an analytical relation connecting the flux fluctuation and the spin structure factor, and explain the evolution of diffusive peak in terms of the roughening of magnetic fluxes.