  Gauge theory with light flavor quark is studied by embedding a D7 brane in a
deconfinement phase background newly constructed. We find a phase transition by
observing a jump of the vacuum expectation value of quark bilinear and also of
the derivative of D7 energy at a critical temperature. For the model considered
here, we also study quark-antiquark potential to see some possible quark-bound
states and other physical quantities in the deconfinement phase.
