  NJL interactions are introduced into the D3/ probe D7 system using Witten's
double trace operator prescription which includes the operator as a classical
term in the effective potential. In the supersymmetric system they do not
induce chiral symmetry breaking which we attribute to the flat effective
potential with quark mass in the supersymmetric theory. If additional
supersymmetry breaking is introduced then standard NJL behaviour is realized.
In examples where chiral symmetry breaking is not preferred such as with a B
field plus an IR cut off chiral condensation is triggered by the NJL
interaction at a second order transition after a finite critical coupling. If
the model already contains chiral symmetry breaking, for example in the B field
case with no IR cut off, then the NJL interaction enhances the quark mass at
all values of the NJL coupling. We also consider the system at finite
temperature: the temperature discourages condensation but when combined with a
magnetic field we find regions of parameter space where the NJL interaction
triggers a first order chiral transition above a critical coupling.
