Topological edge states in photonic Floquet insulator with unpaired Dirac cones

Abstract

Topological insulators are most frequently constructed using lattices with specific degeneracies in their linear spectra, such as Dirac points. For a broad class of lattices, such as honeycomb ones, these points and associated Dirac cones generally appear in non-equivalent pairs. Simultaneous breakup of the time-reversal and inversion symmetry in systems based on such lattices may result in the formation of the unpaired Dirac cones in bulk spectrum, but the existence of topologically protected edge states in such structures remains an open problem. Here photonic Floquet insulator on honeycomb lattice with unpaired Dirac cones in its spectrum is introduced that can support unidirectional edge states appearing at the edge between two regions with opposite sublattice detuning. Topological properties of this system are characterized by the nonzero valley Chern number. Remarkably, edge states in this system can circumvent sharp corners without inter-valley scattering even though there is no total forbidden gap in the spectrum. Our results reveal unusual interplay between two different physical mechanisms of creation of topological edge states based on simultaneous breakup of different symmetries of the system.

arXiv comment9 pages, 7 figures. To appear in Photonics Research. Comments are welcome

References in corpus (48)

• The electronic properties of graphene
• Berry Phase Effects on Electronic Properties
• Topological Photonics
• Topological Photonics
• Photonic Floquet Topological Insulators
• Valley contrasting physics in graphene: magnetic moment and topological transport
• Analogs of quantum Hall effect edge states in photonic crystals
• Nonlinear topological photonics
• Exciton-polariton topological insulator
• Classical higher-order topological insulators
• Direct Observation of Valley-polarized Topological Edge States in Designer Surface Plasmon Crystals
• Observation of Photonic Topological Valley-Hall Edge States
• Photonic Topological Insulator in Synthetic Dimensions
• Photonic Topological Anderson Insulators
• Optical Resonator Analog of a Two-Dimensional Topological Insulator
• Observation of Topological Band Gap Solitons
• Experimental observation of optical Weyl points
• Polariton $\mathbb{Z}$ Topological Insulator
• Nonlinear second-order photonic topological insulators
• Light control with Weyl semimetals
• Unveiling pseudospin and angular momentum in photonic graphene
• Anomalous Topological Phases and Unpaired Dirac Cones in Photonic Floquet Topological Insulators
• Observation of strong backscattering in valley-Hall photonic topological interface modes
• Observation of Edge Solitons in Photonic Graphene
• Network Models of Photonic Floquet Topological Insulators
• Hybrid topological photonic crystals
• Exploring nonlinear topological states of matter with exciton-polaritons: Edge solitons in kagome lattice
• Observation of an unpaired photonic Dirac point
• Topological edge states and gap solitons in the nonlinear Dirac model
• Lieb polariton topological insulators
• Tight-binding methods for general longitudinally driven photonic lattices -- edge states and solitons
• Vector Topological Edge Solitons in Floquet Insulators
• Edge Solitons in Lieb Topological Floquet Insulators
• Observation of nonlinear disclination states
• Topological dipole Floquet solitons
• Transport properties in the photonic super-honeycomb lattice - a hybrid fermionic and bosonic system
• Flatband Line States in Photonic Super-Honeycomb Lattices
• Observation of $\pi$ solitons in oscillating waveguide arrays
• Bragg solitons in topological Floquet insulators
• Interface states in polariton topological insulators
• Dark topological valley Hall edge solitons
• Visual observation of optical Floquet-Bloch oscillations
• Valley Hall edge solitons in a photonic graphene
• Conical intersections for light and matter waves
• Vector valley Hall edge solitons in superhoneycomb lattices
• Floquet edge solitons in modulated trimer waveguide arrays
• Tachyonic Dispersion in Coherent Networks
• Floquet topological insulators with hybrid edges