Emergent Berry Curvature in Inversion-Symmetric Photonic Crystals for Ultraconfined Topological States.

ABSTRACT: An interface between two periodic structures is topological when the global periodicity cannot be restored through local deformations. In time-reversal symmetric photonic crystals, such interfaces typically form between structures with distinct topological phases characterized by nonzero Berry curvature, which is conventionally induced by breaking spatial inversion symmetry through the modifications of air hole sizes and positions. Here, a topological interface is formed between photonic crystals by breaking the unit cell inversion symmetry via spatial shifts ( Δy=±a3${{\Delta}}y = \pm \frac{a}{{\sqrt 3 }}$ ). This modifies the rotational symmetry of a honeycomb photonic crystal unit cell from C₆ to C₃, which induces nonzero Berry curvature in the lower photonic band.

SUBMITTER: Tan YJ 

PROVIDER: S-EPMC12783953 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature