  We consider a D7-brane probe of AdS$_{5}\times S^5$ in the presence of pure
gauge $B$-field. In the dual gauge theory, the $B$-field couples to the
fundamental matter introduced by the D7-brane and acts as an external magnetic
field. The $B$-field supports a 6-form Ramond-Ramond potential on the D7-branes
world volume that breaks the supersymmetry and enables the dual gauge theory to
develop a non-zero fermionic condensate. We explore the dependence of the
fermionic condensate on the bare quark mass $m_{q}$ and show that at zero bare
quark mass a chiral symmetry is spontaneously broken. A study of the meson
spectrum reveals a coupling between the vector and scalar modes, and in the
limit of weak magnetic field we observe Zeeman splitting of the states. We also
observe the characteristic $\sqrt{m_{q}}$ dependence of the ground state
corresponding to the Goldstone boson of spontaneously broken chiral symmetry.
