Realization of photonic  p-orbital higher-order topological insulators

Zhang, Yahui; Bongiovanni, Domenico; Wang, Ziteng; Wang, Xiangdong; Xia, Shiqi; Hu, Zhichan; Song, Daohong; Jukić, Dario; Xu, Jingyi; Morandotti, Roberto; Buljan, Hrvoje; Chen, Zhigang

doi:10.1186/s43593-022-00039-7

Cited by 33 publications

(18 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The degeneracy of the corner states indicates that the three corners in a finite-sized HCL can be decoupled with each other, thus one corner state can occupy only one corner. However, the three corners in a finite-sized BKL tend to couple with each other due to the finite-size effect, which breaks the zero-energy mode degeneracy and leads to mode beating and “fractionalization” of light to all three corners. ,,, Briefly speaking, the eigenstates of gapless zero-energy corner modes in finite-sized HCLs only distribute in one corner, while those in finite-sized BKLs distribute in all three corners, leading to corner mode localization at one corner in the HCLs, but not in the BKLs after long-distance propagation.…”

Section: Results and Discussionmentioning

confidence: 99%

Realization of Topological Corner States in Tailored Photonic Graphene

Xie,

Yan,

Xia

et al. 2024

ACS Photonics

Self Cite

View full text Add to dashboard Cite

Higher-order topological semimetals (HOTSMs) represent a novel type of gapless topological phase, hosting boundary states with dimensions at least two lower than those of their bulk geometry. Such nontrivial boundary states have been predicted and observed in three-dimensional (3D) gapless topological systems, representing features of the HOTSMs. However, their two-dimensional (2D) analogs, represented especially by the corner states in monolayer graphene-like structures, have thus far remained only a theoretical exploration. Here, we experimentally demonstrate nontrivial corner states in specially tailored photonic graphene hosting Dirac points, manifesting the HOTSM-like property in a 2D photonic setting. Such corner states in the otherwise gapless system exhibit distinct phase structures depending on the lattice corner and edge geometry, and are completely degenerate with the zero-energy edge states. Remarkably, we find that these "gapless" corner states remain intact at zero-energy even in a finite-sized graphene lattice, protected by chiral symmetry. Unlike corner states in higher-order topological insulators or topological crystalline insulators with certain rotational symmetry, these corner states are localized exclusively to one corner without any coupling to the bulk or other corners, despite longdistance propagation.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Realization of Topological Corner States in Tailored Photonic Graphene

Xie,

Yan,

Xia

et al. 2024

ACS Photonics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Topological photonic crystals (PCs) can be serving as a versatile platform for controlling light transmission [1,2]. Higher-order topological insulators and topological materials of topological PCs have been widely studied [3,4]. Extensive researches have been conducted on the topological phase in PCs to explore its properties [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

All-optical logic gates based on topological edge and corner states in two-dimensional photonic crystals with square dielectric columns

Gao,

Zhou,

et al. 2024

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Recently, with the rapid progress in all-optical networks and optical computing, there is an increasing requirement for more appropriate methods to design all-optical logic gates. Photonic crystals (PCs) can be serving as a versatile platform for manipulating light propagation. The realization of topological edge states (TESs) and topological corner states (TCSs) within high-order topological photonic insulators has attracted extensive attention. In this paper, TESs and TCSs are achieved using honeycomb photonic crystals (PCs) with square dielectric columns instead of conventional cylindrical ones for obtaining a larger photonic energy band gap due to reduction of dielectric column symmetry. TESs with overlapping frequencies can be attained by different arrangements of combining two PCs with distinct topological properties. A sandwich structure comprising both topologically trivial and non-trivial PCs is proposed, and "AND Gate" and "OR Gate" logic gates are implemented through the coupling between edge state waveguides when controlling the number of coupling layers. Additionally, a triangular-shaped box structure composed of non-trivial PCs enveloped by trivial PCs is constructed. Within this structure, TCSs manifest only around each acute angle, and a "NOT Gate" logic gate is realized through corner state coupling and edge state coupling. This work paves a new way of designing high-performance micro-nano all-optical logic gate devices.

show abstract

“…[19,[32][33][34][35] Recently, there is an emerging type of topological systems, where orbital degree of freedoms (DOF) is introduced into for multiplexing. [36,37] Most of the previously reported topological insulators focus on designing a single structure to obtain one type of topological insulator.…”

Section: Introductionmentioning

confidence: 99%

Multi‐Type Topological States in Higher‐Order Photonic Insulators Based on Kagome Metal Lattices

Tao,

Liu,

Zhou

et al. 2023

Advanced Optical Materials

View full text Add to dashboard Cite

Tunability of topological photonic structures opens a new avenue for photonics research. The rich physical characteristics of the topological photonics have great significance in practical implementations. In this paper, multi‐type topological states are demonstrated in higher‐order photonic topological insulators based on Kagome metal lattices. By stretching or rotating Kagome metal lattices, two types of topological insulators are obtained, and multi‐type topological states are observed. By stretching Kagome metal lattices, a 1D topological edge state and two types of higher‐order topological corner states (corresponding to a traditional higher‐order topological corner state based on nearest‐neighbor coupling and a new higher‐order corner state caused by long‐range interactions) are obtained in a classical quantization of dipole moments higher‐order topological insulators. By rotating Kagome metal lattices, dual‐band higher‐order valley‐Hall topological insulators are achieved with nodal ring degeneracy. Odd‐type and even‐type topological states are obtained. Achieving reconfigurable, multi‐type, and multi‐band topological insulators by using a single structural unit provides interesting insights into topological photonics and provides an unconventional approach to explore photonic systems and condensed matter physics.

show abstract

Realization of photonic p-orbital higher-order topological insulators

Cited by 33 publications

References 58 publications

Realization of Topological Corner States in Tailored Photonic Graphene

Realization of Topological Corner States in Tailored Photonic Graphene

All-optical logic gates based on topological edge and corner states in two-dimensional photonic crystals with square dielectric columns

Multi‐Type Topological States in Higher‐Order Photonic Insulators Based on Kagome Metal Lattices

Contact Info

Product

Resources

About