Topological quadratic-node semimetal in a photonic microring lattice.

ABSTRACT: Graphene, with its two linearly dispersing Dirac points with opposite windings, is the minimal topological nodal configuration in the hexagonal Brillouin zone. Topological semimetals with higher-order nodes beyond the Dirac points have recently attracted considerable interest due to their rich chiral physics and their potential for the design of next-generation integrated devices. Here we report the experimental realization of the topological semimetal with quadratic nodes in a photonic microring lattice. Our structure hosts a robust second-order node at the center of the Brillouin zone and two Dirac points at the Brillouin zone boundary-the second minimal configuration, next to graphene, that satisfies the Nielsen-Ninomiya theorem. The symmetry-protected quadratic nodal point, together wi

SUBMITTER: Gao Z 

PROVIDER: S-EPMC10238381 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature