The metasurfaces simultaneously exhibit two distinct species of massless Dirac polaritons, namely type-I and type-II. By modifying only the photonic environment via an enclosing cavity, one can manipulate the location of the type-II Dirac points, leading to qualitatively different polariton phases. ...
(i.e., maintaining a gapless state) while preserving the geometrical features of the unit cell. In the absence of nontrivial topological transitions, a gap at the Dirac cones is, herein, avoided through the symmetric placement of the nodes around each chain’s center, thereby nullifying the ...