Fig. 3: Computed neutron scattering intensity within the magnetic model.

a Momentum path in the Brillouin zone of the triangular lattice, b INS intensity for the Hamiltonian \({{{{\mathcal{H}}}}}_{2}\) without inter-plane interaction along the high symmetry lines in momentum space. The color plot shows ED results combined from different clusters up to 27 sites. Due to elsewise overbearing intensity at q = 0, the plotted intensity is adjusted for q = 0, by reducing the plotted intensity and broadening at q = 0 (see “Methods”). The overlayed band dispersion is the single-magnon energy from LSWT. As the ED ground state is a superposition of different degenerate magnetic domains, the compared LSWT energy is plotted as the average of three calculations, corresponding to expansions around in-plane ferromagnetic order, with polarization perpendicular to X₁-, Y₁- or Z₁-bonds. c Calculated powder-averaged INS spectrum from LSWT, for the model in Table 1, including inter-plane exchange couplings. Intensities above ~3.5% of the maximum intensity are cut off due to large intensity at q ≈ 0.