Enhanced light-matter interactions at photonic magic-angle topological transitions

In analogy to Lifshitz transitions in electronic systems, topological transitions have recently attracted widespread attention in photonic metamaterials, metasurfaces, and two-dimensional materials, enabling exotic regimes for light-matter interactions. Here, we discuss and study enhanced photonic local density of states in twisted hyperbolic bilayers, enabled by topological transitions emerging at specific twist angles. Our results enhance the understanding of nanoscale light-matter interactions in stacked optical materials as they are rotated with respect to each other in the context of twistronics and suggest emerging applications of these concepts for photonics, including for the manipulation of radiative heat transfer and the control and harvesting of light at the nanoscale.