The spin-dependent corrections to the static interquark potential are
relevant to describing the fine and hyper-fine splittings of the heavy
quarkonium spectra. We investigate these corrections in SU(3) lattice gauge
theory with the Polyakov loop correlation function as the quark source by
applying the multi-level algorithm. We observe remarkably clean signals for the
spin-dependent potentials up to intermediate distances.Comment: 6 pages, Talk presented at Lattice 2005 (Heavy quark physics