FIG. 8.

Relative differences of ${\mathcal{S}}_{1,501}^z$ (blue) calculated for J_xy = 1, α = 2 and $\langle S_1^{+}{S}_{501}^{-}\rangle$ (red) calculated for J_xy = −1, α = 2 caused by (a) increasing L from 5000 to 10⁴ (with K increasing from 9 to 10) and (b) decreasing ϵ_f from 10⁻¹⁰ to 10⁻¹¹ (with K increasing from 9 to 10).