Landau levels in strained two-dimensional photonic crystals

The principal use of photonic crystals is to engineer the photonic density of states, which controls light-matter coupling. We theoretically show that strained two-dimensional photonic crystals can generate artificial electric and magnetic fields that act on light and we show that particular strain patterns give rise to highly degenerate Landau levels. Since photonic crystals are not in general described by tight-binding models, we employ a multiscale expansion of the full continuum 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.