Titre :

Flat band induced topological photonic Tamm states in stubbed structures: Theory and experiment

Auteur(s) :

Khattou, Soufyane [Auteur]
Université Mohammed Premier [Oujda] = Université Mohammed Ier
Rezzouk, Yamina [Auteur]
Université Mohammed Premier [Oujda] = Université Mohammed Ier
University of Mohammed I - Université Mohammed Premier
El Ghafiani, Mohamed [Auteur]
Université Mohammed Premier [Oujda] = Université Mohammed Ier
Amrani, Madiha [Auteur]
Université Mohammed Premier [Oujda] = Université Mohammed Ier
Elaouni, Mohammed [Auteur]
Université Mohammed Premier [Oujda] = Université Mohammed Ier
Boudouti, El Houssaine El [Auteur correspondant]
Université Mohammed Premier [Oujda] = Université Mohammed Ier
Talbi, Abdelkrim [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Acoustique Impulsionnelle & Magnéto-Acoustique Non linéaire - Fluides, Interfaces Liquides & Micro-Systèmes - IEMN [AIMAN-FILMS - IEMN]
Laboratoire International associé sur les phénomènes Critiques et Supercritiques en électronique fonctionnelle, acoustique et fluidique [LIA LICS/LEMAC]
Akjouj, Abdellatif [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Physique - IEMN [PHYSIQUE - IEMN]
Djafari-Rouhani, Bahram [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Physique - IEMN [PHYSIQUE - IEMN]

Titre de la revue :

Physical Review B

Pagination :

125405, 18 pages

Éditeur :

American Physical Society

Date de publication :

2023-03

ISSN :

2469-9950

Discipline(s) HAL :

Physique [physics]
Sciences de l'ingénieur [physics]

Résumé en anglais : [en]

We provide theoretical and experimental evidence for the existence of topological Tamm states at the interface between two stubbed photonic crystals (PCs) as a function of the period and length of the stubs. Several works ...
Lire la suite >We provide theoretical and experimental evidence for the existence of topological Tamm states at the interface between two stubbed photonic crystals (PCs) as a function of the period and length of the stubs. Several works have addressed these states in the well-known Su-Schrieffer-Heeger model, a dimerized chain based on two resonators per unit cell where the opening of a gap at a Dirac cone results in a symmetry inversion of bulk bands between two topologically different crystals. Here, we give a detailed theoretical analysis of a mechanism based on band-edge symmetry inversion around a flat band, i.e., when the width of the pass band vanishes, while using only one resonator (stub) per unit cell. Then, we propose a simple versatile experimental platform to observe such interface states, which is based on coaxial cables operating in the radio-frequency domain. The investigation of these states was performed by using different approaches: (i) the topology of the bands based on the Zak phase and the symmetry of the band-edge modes, (ii) the sign of the reflection phase between each PC and a waveguide, and (iii) the dips or peaks in the reflection and transmission spectra when two finite photonic crystals are connected together either horizontally or vertically along a waveguide. Furthermore, we give a general rule about the existence of interface states when two PCs exhibit two common gaps with a flat band in their middle and different bulk-edge symmetries. Also, we provide closed-form expressions of the geometrical parameters and the frequency for which the interface state becomes bound state in the continuum (BIC). We show that these topological BIC states are stationary states of the cavity between the two PCs, and are very robust to any perturbation on both sides of the cavity. Finally, we show the impossibility of existence of interface states between two PCs with identical periods and different stubs. The theoretical and experimental results are discussed for both Neumann and Dirichlet boundary conditions at the end of the stubs.Lire moins >

Langue :

Anglais

Vulgarisation :

Non

Collections :

• Institut d'Électronique, de Microélectronique et de Nanotechnologie (IEMN) - UMR 8520

Source :

Harvested from HAL