  We use the AdS/CFT correspondence to compute the AC conductivities for a
(2+1)-dimensional system of massless fundamental fermions coupled to
(3+1)-dimensional Super Yang-Mills theory at strong coupling. We consider the
system at finite charge density, with a constant electric field along the
defect and an orthogonal magnetic field. The holographic model we employ is the
well studied D3/probe-D5-brane system. There are two competing phases in this
model: a phase with broken chiral symmetry favored when the magnetic field
dominates over the charge density and the electric field and a chirally
symmetric phase in the opposite regime. The presence of the electric field
induces Ohm and Hall currents, which can be straightforwardly computed by means
of the Karch-O'Bannon technique.Studying the fluctuations around the stable
configurations in linear response theory, we are able to derive the full
frequency dependence of longitudinal and Hall conductivities in all the regions
of the phase space.
