  In the presence of uniform D-instanton charges, quarks can be confined
although gluons are not, because baryon vertices are allowed due to the net
repulsive force on the on the probe D-branes. Since there is no scale in the
geometry itself apart from the horizon size, there is no Hawking-Page
transition. As a consequence, the D7 brane embedding can encode the effect of
the the finite temperature as well as finite baryon density even for low
temperature. The probe D-brane embedding, however, undergoes a chiral phase
transition according to the temperature and density parameter.
  We studied such phase transitions and calculated the constituent quark mass,
chiral condensation and the binding energy of baryons as function of the
density. The baryon vertex melting is identified as the quark deconfinement. We
draw phase diagram according to these transitions.
