Fig. 11
(a) Derivative of the standard deviation at half-filling, \(\sigma _\text {HF}'(J;L) \equiv \text {d}\sigma _\text {HF}/\text {d}J\), plotted for systems of size \(L=10,\, 39,\, 10^2,\,10^3,\,10^4\), respectively. The horizontal dashed gray line represents the threshold value \(\Delta \sigma =0.02\). (b) Contour plot of \(\sigma _\text {HF}'(J;L)\) for positive values of J and \(L\ge 3\). The red contour lines correspond to \(\sigma _\text {HF}'(J;L) = \Delta \sigma =0.02\).
