Understanding the spin-spin interactions among heavy quarks at finite temperature

In this proceeding, we report the non-perturbative potential between a heavy quark–antiquark pair in a QCD plasma at finite temperature. We compute the spin-dependent component of the thermal potential using temporal Wilson line correlators with insertions of the color-magnetic field. The calculations are performed in quenched QCD at $1.5$ times the deconfinement temperature Td, on a four-dimensional lattice with spatial extent Nₛ = 68, and temporal extents N_τ = 16 and $20$. For the first time, we show that Vₛₛ(r) develops an imaginary part at finite temperature, a feature similar to that observed in the static potential. Finally, we discuss the physical implications of our results for understanding the dissociation of quarkonium bound states in the quark–gluon plasma.