We argue that cold quark matter is a color superconductor. The Cooper pairs of QCD are spin-isospin zero, color anti-triplet diquarks. In this contribution we review some of the available information on the quark-quark interaction in QCD. We show that instantons provide a strongly attractive interaction in the scalar diquark channel. In the high density phase, this interaction leads to diquark Bose condensation with a gap on the order of 50 MeV.
Categories: nucl-th