  We study domain wall fermions and their condensation in the D3/probe D7
system. A spatially dependent mass term for the N=2 hypermultiplet can be
arranged to isolate distinct two component fermions on two 2+1 dimensional
domain walls. We argue that the system shows condensation/mass generation
analogous to the D3/probe D5 anti-D5 system. The chiral condensate and pion
mass can be directly computed on the domain wall. We provide evidence that
these systems with the domains separated by a width w have a bare (current)
quark mass that scales as 1/w when the spatial dependent mass is large. Adding
a magnetic field does not induce chiral symmetry breaking between the separated
domain wall fermions, but a similar phenomenological dilaton factor can be made
strong enough to introduce spontaneous symmetry breaking. We show a
Gell-Man-Oakes-Renner relation for the pions in that case and also for the case
where the D7 probe is in a back-reacted dilaton flow geometry. The vacuum
configurations can also be interpreted as having a spontaneously generated mass
by a Nambu-Jona-Lasinio four fermion operator, depending on the choice of
boundary conditions on fluctuations, according to Witten's multi-trace
prescription.
