Fig. 2.

Neutron scattering intensity $\mathcal{I}\left(\mathbf{k},\omega \right)$ within the nnHK model. a–c Detailed results for Model 1 (J ₁ = −2.2, K ₁ = +7.4 meV): a $\mathcal{I}\left(\mathbf{k},\omega \right)$ computed via LSWT; results are averaged over the three zigzag ordering wavectors, parallel to the X-bonds, Y-bonds, and Z-bonds. Inset: Definition of Brillouin zone and high-symmetry k-points. b ED results, combining data from several 20-site and 24-site periodic clusters (see “Methods”). c ED k-dependence of $\mathcal{I}\left(\mathbf{k},\omega \right)$ integrated over the indicated energies, as obtained from a single 24-site cluster respecting all symmetries of Eq. (1) (see “Methods”). d Comparison of Γ-point intensities for the K ₁ = +7.7 meV AFM spin liquid (exact results^{53, 54}), Model 1 (ED), and the experimental data for α-RuCl₃ ¹². e Evolution of the ED Γ-point intensity with decreasing $∣J_1\mathrm{∕}{K}_1∣$, showing absence of low-energy intensity close to the K ₁ > 0 spin liquid. The top three interaction sets correspond to zigzag order, while the bottom is the K ₁ > 0 spin liquid. For all spectra, a Gaussian broadening of 0.5 meV has been applied