Nanophotonics in infrared and terahertz (THz) frequencies remains elusive, due to the lack of efficient material platforms for tailorable light-matter interactions in those frequencies so far, until recent discovery of emerging van der Waals nanomaterials such as graphene, hexagonal boron nitride, alpha-phase molybdenum trioxide (α-MoO3) and others. Those media present plasmon and phonon polaritonic responses