Nonlinear photonic disclination states

Abstract

Higher-order topological insulators are unusual materials that can support topologically protected states, whose dimensionality is lower than the dimensionality of the structure at least by 2. Among the most intriguing examples of such states are zero-dimensional corner modes existing in two-dimensional higher-order insulators. In contrast to corner states, recently discovered disclination states also belong to the class of higher-order topological states, but are bound to the boundary of the disclination defect of the higher-order topological insulator and can be predicted using the bulk-disclination correspondence principle. Here, we present the first example of the nonlinear photonic disclination state bifurcating from its linear counterpart in the disclination lattice with a pentagonal or heptagonal core. We show that nonlinearity allows to tune location of the disclination states in the bandgap and notably affects their shapes. The structure of the disclination lattice is crucial for stability of these nonlinear topological states: for example, disclination states are stable in the heptagonal lattice and are unstable nearly in the entire gap of the pentagonal lattice. Nonlinear disclination states reported here are thresholdless and can be excited even at low powers. Nonlinear zero-energy states coexisting in these structures with disclination states are also studied. Our results suggest that disclination lattices can be used in the design of various nonlinear topological functional devices, while disclination states supported by them may play an important role in applications, where strong field confinement together with topological protection are important, such as the design of topological lasers and enhancement of generation of high harmonics.

10 pages, 6 figures, to appear in APL Photonics

References in corpus (31)

• Topological Photonics
• Scheme to Achieve Silicon Topological Photonics
• Topological Acoustics
• Observation of topological valley transport of sound in sonic crystals
• Visualization of higher-order topological insulating phases in two-dimensional dielectric photonic crystals
• Direct observation of corner states in second-order topological photonic crystal slabs
• Classical higher-order topological insulators
• Photonic crystal nanocavity based on a topological corner state
• Photonic Topological Anderson Insulators
• Acoustic realization of quadrupole topological insulators
• Polariton $\mathbb{Z}$ Topological Insulator
• Low-threshold topological nanolasers based on second-order corner state
• Nonlinearity-induced photonic topological insulator
• Optical soliton formation controlled by angle twisting in photonic moiré lattices
• Crystalline metamaterials for topological properties at subwavelength scales
• Nonlinear second-order photonic topological insulators
• Quantized Nonlinear Thouless Pumping
• Topologically protected valley-dependent quantum photonic circuits
• Nonlinear Thouless pumping: solitons and transport breakdown
• Higher-order topological phases in tunable $C_3$-symmetric photonic crystals
• Cavity Quantum Electrodynamics with Second-Order Topological Corner State
• Observation of edge solitons in topological trimer arrays
• Nonlinear imaging of nanoscale topological corner states
• Nonlinear imaging of nanoscale topological corner states
• Observation of degenerate zero-energy topological states at disclinations in an acoustic lattice
• Vortex states in an acoustic Weyl crystal with a topological lattice defect
• Nonlinear Topological Valley Hall Edge States Arising from Type-II Dirac Cones
• Bimorphic Floquet Topological Insulators
• Tight-binding methods for general longitudinally driven photonic lattices -- edge states and solitons
• Bound States of Conical Singularities in Graphene-Based Topological Insulators
• Theory of Topological Corner State Laser in Kagome Waveguide Arrays

Cited by in corpus (7)

• Observation of nonlinear disclination states
• Vortex solitons in topological disclination lattices
• Quadratic solitons in higher-order topological insulators
• Vortex solitons in disclination quasicrystals
• Polariton Topological Insulators with Disclinations
• Topological linear and nonlinear gap modes in defected dimer lattice with fourth-order diffraction
• Stable vortex soliton arrays in disclination-fractal systems