  We holographically engineer a periodic lattice of localized fermionic
impurities within a plasma medium by putting an array of probe D5-branes in the
background produced by N D3-branes. Thermodynamic quantities are computed in
the large N limit via the holographic dictionary. We then dope the lattice by
replacing some of the D5-branes by anti-D5-branes. In the large N limit, we
determine the critical temperature below which the system dimerizes with bond
ordering. Finally, we argue that for the special case of a square lattice our
system is glassy at large but finite N, with the low temperature physics
dominated by a huge collection of metastable dimerized configurations without
long-range order, connected only through tunneling events.
