Spatial topological materials
Spatial topological materials
Conventional topological materials rely on band-specific mechanisms -- such as band inversion or spin-orbit coupling -- to realize nontrivial topological invariants. Here, we introduce a symmetry-driven paradigm for generating topological states, exploiting a translational symmetry $\mathcal{L}$ that couples two maximal Wyckoff positions. This symmetry induces robust band degeneracies independent of band structure details, allowing us to classify $\mathcal{L}$ as trivial or nontrivial by quantized electric multipoles. Crucially, for nontrivial $\mathcal{L}$, symmetry-protected edge and corner states emerge universally across all symmetry-compatible insulating, semi-metallic, and metallic phases, irrespective of specific band structure. We demonstrate this in a $C_4$-symmetric model and validate it using an experimentally feasible dielectric photonic crystal engineered with $\mathcal{L}$ symmetry. Through full-wave simulation, we observe directional edge modes and localized corner modes, with the former selectively excited by harmonic point sources spatially shifted by $\mathcal{L}$ at a fixed frequency.
Qinghua He、Wenlong Gao、Feng Liu
物理学
Qinghua He,Wenlong Gao,Feng Liu.Spatial topological materials[EB/OL].(2025-06-20)[2025-07-21].https://arxiv.org/abs/2405.14165.点此复制
评论