English

Semiclassical Routes to the $\alpha$-RuCl$_3$ Scattering Continuum via Model Meta$-$Analysis

Materials Science 2026-02-12 v1 Strongly Correlated Electrons

Abstract

α\alpha-RuCl3_3 is a leading material for proximate Kitaev magnetism. We address the origin of the broad, Γ\Gamma-point centered excitation continuum observed by inelastic neutron scattering at elevated temperatures in this compound. Using stochastic Landau-Lifshitz dynamics augmented with quantum-equivalent corrections, we reproduce the temperature-dependent dynamical spin structure factor across both the correlated and conventional paramagnetic regimes. A meta-analysis of 38 published exchange parameter sets identifies those most consistent with the full temperature evolution. A Bayesian optimization procedure is used to derive parameters that capture the low-energy star-like momentum dependence and the overall bandwidth of the continuum. Rescaling temperatures by the Curie--Weiss scale produces a collapse of spectral measures, demonstrating that the high-TT dynamics are governed by correlated paramagnetism below θCW\theta_{\mathrm{CW}} rather than by the Kitaev crossover to fractionalized excitations. Complementary 24-site exact diagonalization clarifies finite-size systematics at low temperature and the proximity to zigzag/incommensurate ordering. Beyond α\alpha-RuCl3_3, our simulation pipeline provides a reproducible, data-driven framework to infer effective spin models in magnets that exhibit broad continua.

Keywords

Cite

@article{arxiv.2602.10190,
  title  = {Semiclassical Routes to the $\alpha$-RuCl$_3$ Scattering Continuum via Model Meta$-$Analysis},
  author = {Chaebin Kim and Martin Mourigal},
  journal= {arXiv preprint arXiv:2602.10190},
  year   = {2026}
}

Comments

14 pages, 11 figures, plus Supplementary information about the table of 38 published exchange parameter sets