  By using AdS/CFT, we study the critical electric field, the Schwinger pair
creation rate and the potential phase diagram for the quark and anti quark in
four confining supergravity backgrounds which are the Witten QCD, the
Maldacena-Nunez, the Klebanov-Tseytlin and the Klebanov-Strassler models. We
compare the rate of phase transition in these models and compare it also with
the conformal case. We then present the phase diagrams of the entanglement
entropy of a strip in these geometries and find the predicted butterfly shape
in the diagrams. We find that the phase transitions have higher rate in WQCD
and KT relative to MN and KS. Finally we show the effect of turning on an
additional magnetic field on the rate of pair creation by using the imaginary
part of the Euler-Heisenberg effective Lagrangian. The results is increasing
the parallel magnetic field would increase the pair creation rate and
increasing the perpendicular magnetic field would decrease the rate.
