  We study the interplay between chiral and diquark condensates within the
framework of the Ginzburg-Landau free energy, and classify possible phase
structures of two and three-flavor massless QCD. The QCD axial anomaly acts as
an external field applied to the chiral condensate in a color superconductor
and leads to a crossover between the broken chiral symmetry and the color
superconducting phase, and, in particular, to a new critical point in the QCD
phase diagram.
