Abstract: The physics of quarkonium created in heavy-ion collisions is intrinsically connected to the correlation functions of adjoint chromoelectric fields in quantum chromo-dynamics. In this talk I will discuss the study of such correlation functions in a weak-coupling expansion at next-to-leading order in a thermal medium. The results are shown to agree well with recent lattice calculations at high temperatures. I will then discuss the spectral function associated with these correlation functions and possible implications the results have on the lattice.