  We show that strongly coupled holographic matter at finite charge density can
exhibit charge density wave phases which spontaneously break translation
invariance while preserving time-reversal and parity invariance. We show that
such phases are possible within Einstein-Maxwell-dilaton theory in general
spacetime dimensions. We also discuss related spatially modulated phases when
there is an additional coupling to a second vector field, possibly with
non-zero mass. We discuss how these constructions, and others, should be
associated with novel spatially modulated ground states.
