We have theoretically and experimentally achieved large-area one-way transport by using heterostructures consisting of a domain an ordinary photonic crystal (PC) sandwiched between two domains magnetic PCs. The non-magnetized carries orthogonal waveguide states which amplitude uniformly distributed over large-area. These support unidirectional even though the medium propagation is not magnetized. show both numerically that such can be utilized to abruptly narrow beam width extended state...

Quantized charge pumping is a robust adiabatic phenomenon uniquely existing in topologically nontrivial systems. Such topological not only brings fundamental insights to the evolution of states under protection topology but also provides vital approach for study higher-dimensional phases. In this work, we demonstrate an acoustic waveguide system by showing successful boundary (TBSs) across bulk opposite edge. By exploring finite-size induced mini-gap between two TBS bands, unveil...

Electromagnetic wave propagation in three-dimensional (3D) space typically suffers omnidirectional scattering when encountering obstacles. In this study, we used Chern vectors to construct a topological heterostructure, where large-volume nonreciprocal transport 3D is achieved. The shape of the cross section heterostructure can be arbitrary designed, and experimentally observed distinctive cross-shaped field pattern transport, energy harvesting, remarkable ability electromagnetic traverse...

The concept of gauge field is a cornerstone modern physics and the synthetic has emerged as new way to manipulate particles in many disciplines. In optics, several schemes Abelian fields have been proposed. Here, we introduce platform for realizing SU(2) non-Abelian acting on two-dimensional optical waves wide class anisotropic materials discover novel phenomena. We show that virtual Lorentz force arising from material anisotropy can induce light beams travel along Zitterbewegung...

Recently, higher-order topologies have been experimentally realized, featuring topological corner modes (TCMs) between adjacent topologically distinct domains. However, they to comply with specific spatial symmetries of underlying lattices, hence their TCMs only emerge in very limited geometries, which significantly impedes generic applications. Here, we report a general scheme inducing arbitrary geometry based on Dirac vortices from aperiodic Kekul\'e modulations. The can now be constructed...

Abstract Nodal lines are degeneracies formed by crossing bands in three-dimensional momentum space. Interestingly, these degenerate can chain together via touching points and manifest as nodal chains. These chains usually embedded two orthogonal planes protected the corresponding mirror symmetries. Here, we propose demonstrate an in-plane photonics, where all chained coexist a single plane instead of ones. The point is stabilized intrinsic symmetry that specific to electromagnetic waves at Г...

Nodal lines are symmetry-protected one-dimensional band degeneracies in momentum space, which can appear numerous topological configurations such as nodal rings, chains, links, and knots. Very recently, non-Abelian physics have been proposed space-time inversion (PT) symmetric systems. One of the most special systems is earring link, composing a chain linking with an isolated line. Such links not observed real We designed phononic crystals experimentally two different kinds by measuring...

That disorder can induce nontrivial topology is a surprising discovery in topological physics. As typical example, Chern Anderson insulators (TAIs) have been realized photonic systems, where the phases exist without symmetry protection. In this Letter, by taking transverse magnetic and electric polarizations as pseudospin degrees of freedom, we theoretically propose scheme to realize disorder-induced symmetry-protected phase transitions two-dimensional crystals with combined time-reversal,...

Chiral zeroth Landau levels are topologically protected bulk states that give rise to chiral anomaly. Previous discussions on such based three-dimensional Weyl degeneracies. Their realizations using two-dimensional Dirac point systems, being more promising for future applications, were never reported before. Here we propose a theoretical and experimental scheme realizing in photonic system. By introducing an inhomogeneous effective mass through breaking local parity inversion symmetries, the...

Abstract In non-Hermitian systems, defective band degeneracies called exceptional points can form lines (ELs) in 3D momentum space the absence of any symmetries. However, whether presence symmetries affect EL configurations had rarely been discussed. Here we show that a natural orientation be assigned to every according eigenenergy braiding around it, and establish source-free principle ELs stating number ingoing outgoing from junction must conserved. Based on this principle, discover three...

The Chern number has been widely used to describe the topological properties of periodic structures in momentum space. Here, we introduce a real-space spin for optical near fields finite-sized structures. This new is intrinsically quantized and equal structure's Euler characteristic. relationship robust against continuous deformation geometry irrelevant specific material constituents or external excitation. Our Letter enriches physics by extending real space, opening exciting possibilities...

We present the new concept of photonic alloy as a non-periodic topological material. By mixing non-magnetized and magnetized rods in 2D crystal configuration, we realized alloys microwave regime. Our experimental findings reveal that sustains non-reciprocal chiral edge states (CESs) even at very low concentration rods. The non-trivial topology associated these systems can be characterized by winding reflection phase. results indicate threshold concentrations for investigated system within...

The topological invariants of a periodic system can be used to define the phase each band and determine existence interface states within certain bandgap. Here, we propose scheme based on full diagrams, design any specified bandgaps. As an example, here kind one-dimensional phononic crystals. By connecting two semi-infinite structures with different phases, specific bandgap or their combinations achieved in rational manner. single bandgap, all odd bandgaps, even are verified simulations...

Abstract Very recently, increasing attention has been focused on non-Abelian topological charges, e.g., the quaternion group Q 8 . Different from Abelian band insulators, these systems involve multiple entangled bulk bandgaps and support nontrivial edge states that manifest features. Furthermore, a system with an even or odd number of bands will exhibit significant difference in classification. To date, there scant research investigating even-band insulators. Here, we both theoretically...

The robust transport of edge modes is perhaps the most useful property topological materials. existence guaranteed by bulk-edge correspondence, which states that number determined bulk invariants. To obtain on edge, we need to make volumetric changes many atoms control properties a few in lower dimension. We suggest here can do reverse some cases: guarantee chiral phenomena modes, achieving are essentially same as those observed valley-Hall systems. Specifically, show topologically trivial...

Low-energy electrons near Dirac/Weyl nodal points mimic massless relativistic fermions. However, as they are not constrained by Lorentz invariance, can exhibit tipped-over type-II cones that provide highly anisotropic physical properties and responses, creating unique possibilities. Recently, have been observed in several quantum classical systems. Yet, there is still no simple deterministic strategy to realize them since their accidental degeneracies, unlike symmetry-guaranteed type-I...

An astroid-shaped loop of exceptional points (EPs), comprising four cusps, is found to spawn from the triple degeneracy point in Brillouin zone (BZ) a Lieb lattice with nearest-neighbor hoppings when non-Hermiticity introduced. The occurrence EP due realness discriminant which guaranteed by non-Hermitian chiral symmetry. EPs at cusps involve coalescence three eigenstates, combined result symmetry and mirror-T exactly an astroid limit infinitesimal non-Hermiticity. expands...

Scattering immune propagation of light in topological photonic systems may revolutionarize the design integrated circuits for information processing and communications. In optics, various have been developed, which were based on classical emulation either quantum spin Hall effect or valley effect. On other hand, combination both degrees freedom can lead to a new kind transport phenomenon, dubbed (QSVH), further expand number topologically protected edge channels would be useful multiplexing....