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Related papers: Topology-optimized Dual-Polarization Dirac Cones

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Recently, topological Dirac-vortex modes in Kekul\'e-distorted photonic lattices have attracted broad interest and exhibited promising applications in robust photonic devices such as topological cavities, lasers, and fibers. However, due to…

In this paper, we explore the topological behavior of a two-dimensional honeycomb photonic crystal (PC) based on the presence of double Dirac-cone connected the orbitals p and d, due to the C6 point group symmetry of the hexagonal PCs.…

Applied Physics · Physics 2020-06-15 Jamileh Hajivandi , Hasan Pakarzadeh , Hamza Kurt

This letter investigates a flow-free, pseudospin-based acoustic topological insulator. Zone folding, a strategy originated from photonic crystal, is used to form double Dirac cones in phononic crystal. The lattice symmetry of the phononic…

Mesoscale and Nanoscale Physics · Physics 2017-12-06 Yuanchen Deng , Hao Ge , Yuan Tian , Minghui Lu , Yun Jing

The interband optical absorption of linearly polarised light by two-dimensional (2D) semimetals hosting tilted and anisotropic Dirac cones in the bandstructure is analysed theoretically. Super-critically tilted (type-II) Dirac cones are…

Mesoscale and Nanoscale Physics · Physics 2022-06-09 A. Wild , E. Mariani , M. E. Portnoi

We show that a planar array of bipolar waveguides in graphene can be used to engineer gapped and tilted two-dimensional Dirac cones within the electronic band structure. The presence of these gapped and tilted Dirac cones is demonstrated…

Mesoscale and Nanoscale Physics · Physics 2024-12-02 A. Wild , R. R. Hartmann , E. Mariani , M. E. Portnoi

The newly discovered topological crystalline insulators (TCIs) harbor a complex band structure involving multiple Dirac cones. These materials are potentially highly tunable by external electric field, temperature or strain and could find…

Periodically driven systems can host so called anomalous topological phases, in which protected boundary states coexist with topologically trivial Floquet bulk bands. We introduce an anomalous version of reflection symmetry protected…

Mesoscale and Nanoscale Physics · Physics 2019-07-02 Konstantinos Ladovrechis , Ion Cosma Fulga

Photonic crystals have been demonstrated as a versatile platform for the study of topological phenomena. The recent discovery of higher order topological insulators introduces new aspects of topological photonic crystals which are yet to be…

Optics · Physics 2021-02-02 Shiqiao Wu , Bin Jiang , Yang Liu , Jian-Hua Jiang

Aiming at the promising superlensing for the medical ultrasonic and detection, the double-negative metamaterials which possess the negative mass density and elastic modulus simultaneously can be acted as the ideal superlens for breaking the…

Materials Science · Physics 2018-11-09 Hao-Wen Dong , Sheng-Dong Zhao , Yue-Sheng Wang , Chuanzeng Zhang

The studies of topological phases of matter have been extended from condensed matter physics to photonic systems, resulting in fascinating designs of robust photonic devices. Recently, higher-order topological insulators (HOTIs) have been…

Mesoscale and Nanoscale Physics · Physics 2019-06-19 Bi-Ye Xie , Guang-Xu Su , Hong-Fei Wang , Hai Su , Xiao-Peng Shen , Peng Zhan , Ming-Hui Lu , Zhen-Lin Wang , Yan-Feng Chen

The classical adjoint-based topology optimization (TO) method, based on the use of a random continuous dielectric function as an adjoint variable distribution, is known to be one of the most efficient optimization methods that enable the…

Optics · Physics 2023-11-01 Kofi Edee , Mauro Antezza , Brahim Guizal

Valley photonic crystals (VPCs) offer topological kink states that ensure robust, unidirectional, and backscattering-immune light propagation. The design of VPCs is typically based on analogies with condensed-matter topological insulators…

Topological phases arise from the elegant mathematical structures imposed by the interplay between symmetry and topology1-5. From gapped topological insulators to gapless semimetals, topological materials in both quantum and classical…

The extraordinary electronic properties of Dirac materials, the two-dimensional partners of Weyl semimetals, arise from the linear crossings in their band structure. When the dispersion around the Dirac points is tilted, the emergence of…

Mesoscale and Nanoscale Physics · Physics 2019-07-31 M. Milićević , G. Montambaux , T. Ozawa , I. Sagnes , A. Lemaître , L. Le Gratiet , A. Harouri , J. Bloch , A. Amo

Photonic crystal fibers (PCFs) that trap and guide light using photonic bandgaps have revolutionized modern optics with enormous scientific innovations and technological applications spanning many disciplines. Recently, inspired by the…

Different from the Fermi surface of the type-I Dirac semimetal being a point, that of the type-II Dirac semimetal is a pair of crossing lines because the Dirac cone is tilted with open and hyperbolic isofrequency contours. As an optical…

Topological insulators are innovative materials with semiconducting bulk together with surface states forming a Dirac cone, which ensure metallic conduction in the surface plane. Therefore, topological insulators represent an ideal platform…

Applied Physics · Physics 2019-04-02 Antonio Politano , Leonardo Viti , Miriam S. Vitiello

The study of band topology in photonic crystals was primarily focused on near-field effects, including edge states and high order corner states. However, this work investigated the polarization distribution of radiated fields for photonic…

Optics · Physics 2024-08-27 Zhang Jiawei , Liu Andong , Wang Jin , Dong Zheng-Gao

Although several efforts have been taken to enhance the photonic spin Hall shift in deep-subwavelength region, according to effective medium theory, the fundamental confliction between near-zero reflection coefficient and near-zero incident…

Degeneracy is an omnipresent phenomenon in various physical systems, which has its roots in the preservation of geometrical symmetry. In electronic and photonic crystal systems, very often this degeneracy can be broken by virtue of strong…

Optics · Physics 2022-11-23 Steffen Börm , Fatemeh Davoodi , Ralf Köhl , Nahid Talebi