Figure 3

The magnitude of the spin-spin correlation function $\left|\langle S_i^z{S}_j^z\rangle \right|$ at half filling as a function of distance $d/a$ for $T/t=0.2$ (circles) and 1.0 (squares) for a 16-site (black online) and 50-site (red online) cluster for $U/t=8$ and $n=1$. For $T=1.0$ the extrapolation to the TL is shown with exponential fit $|\langle S_i^z{S}_j^z\rangle |=A{e}^{-d/\xi }$ with $\xi \approx 0.417$ and $A=\langle {S_i^z}^2\rangle \approx 0.89$.