Free energy and potential energy of static quark anti-quark pair at T$>$0

I will discuss lattice QCD calculations of the free energy and the potential energy of static quark anti-quark pair at non-zero temperature using highly improved staggered quark (HISQ) action. The free energy of static quark anti-quark pair is calculated from the correlation functions of Polyakov loops, while the potential energy is extracted from the analysis of temporal Wilson loops with time extent $\tau<1/T$. I will show that chromo-electric screening effects are not visible in the potential energy for distances $r<1$ fm and temperatures $T<200$ MeV, and the temperature dependence of the free energy can be understood in terms of hadronic degrees of freedom. I will also discuss the implication of these findings on quarkonium properties in quark-gluon plasma.