  The principal use of photonic crystals is to engineer the photonic density of
states, which controls light-matter coupling. We theoretically show that
strained 2D photonic crystals can generate artificial electromagnetic fields
and highly degenerate Landau levels. Since photonic crystals are not described
by tight-binding, we employ a multiscale expansion of the full wave equation.
Using numerical simulations, we observe dispersive Landau levels which we show
can be flattened by engineering a pseudoelectric field. Artificial fields yield
a design principle for aperiodic nanophotonic systems.
