  AdS plane waves describe simple backgrounds which are dual to anisotropically
excited systems with energy fluxes. Upon dimensional reduction, they reduce to
hyperscaling violating spacetimes: in particular, the $AdS_5$ plane wave is
known to exhibit logarithmic behavior of the entanglement entropy. In this
paper, we carry out an extensive study of the holographic entanglement entropy
for strip-shaped subsystems in AdS plane wave backgrounds. We find that the
results depend crucially on whether the strip is parallel or orthogonal to the
energy current. In the latter case, we show that there is a phenomenon
analogous to a phase transition.
