Tunable Topological Refractions in Valley Sonic Crystals With Triple Valley Hall Phase Transitions (Invited Paper)

Jia, Ding; Wang, Yin; Ge, Yong; Yuan, Shouqi; Sun, Hong-xiang

doi:10.2528/pier21102002

Cited by 27 publications

(11 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In recent years, non-Hermitian physics has attracted great attention owing to its rich physical significances and various practical applications [1][2][3][4]. Exceptional point (EP) is a unique feature for non-Hermitian systems, which has become a hot topic in photonics [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], mechanics [20][21][22][23][24][25][26], and acoustics [27][28][29][30][31][32][33][34][35][36][37][38][39] owing to its great potential in energy transport. In acoustics, based on parity-time symmetric systems [27][28][29][30][31][32], researchers have realized EP by introducing balanced gain and loss which can be obtained by a pair of electro-acoustic resonators loaded with specifically tailored circuits [30] and by a composite structure composed of...…”

Section: Introductionmentioning

confidence: 99%

Exceptional Ring by Non-Hermitian Sonic Crystals

Wang¹,

Ge²,

Yuan³

et al. 2023

PIER

View full text Add to dashboard Cite

Exceptional point (EP) and exceptional ring (ER) are unique features for non-Hermitian systems, which have recently attracted great attentions in acoustics due to their rich physical significances and various potential applications. Despite the rapid development about the study of the EP and ER in one-dimensional acoustic systems, the realization of them in two-dimensional (2D) non-Hermitian structures is still facing a great challenge. To overcome this, we numerically and theoretically realize an ER in 2D reciprocal space based on a square-lattice non-Hermitian sonic crystal (SC). By introducing radiation loss caused by circular holes of each resonator in a Hermitian SC, we realize the conversion between a Dirac cone and the ER. Based on the theoretical analysis with the effective Hamiltonian, we obtain that the formation of the ER is closely related to different radiation losses of dipole and quadrupole modes in the resonators. Additionally, in the non-Hermitian SC, two eigenfunctions can be merged into a single self-orthogonal one on the ER, which does not exist in the Hermitian SC. Finally, by verifying the existence of the EP with topological characteristics in every direction of 2D reciprocal space, we further demonstrate the ER in the proposed non-Hermitian SC. Our work may provide theoretical schemes and concrete methods for designing various types of non-Hermitian acoustic devices.

show abstract

Section: Introductionmentioning

confidence: 99%

Exceptional Ring by Non-Hermitian Sonic Crystals

Wang¹,

Ge²,

Yuan³

et al. 2023

PIER

View full text Add to dashboard Cite

show abstract

“…In addition to its robust valley transports, topological refractions of valley edge states from an impedance-mismatched zigzag interface between the VSCs and external medium have also become a hot topic in acoustics [21][22][23][24][25][26][27], which has a unique advantage of reflection-free sound refraction owing to the suppression of intervalley scattering. In previously demonstrated topological refractions, when the output wave vector of topological refractions is in the range of the 1st Brillouin zone of the VSCs, a single-beam topological refraction is generally obtained in topological waveguides composed of two VSCs, providing the feasibility of designing a directional acoustic antenna [21,22,24,25].…”

Section: Introductionmentioning

confidence: 99%

“…However, when the working band of the edge state moves into the high-frequency region gradually, the output wave vectors of the topological refraction are beyond the range of the 1st Brillouin zone of the VSCs. Thus, the output sound energy is featured as the form of a double-beam or multi-beam topological refraction based on the phase-matching condition [23,26,27], which becomes an obstacle for designing robust directional antennas and communication devices in the high-frequency band.…”

Section: Introductionmentioning

confidence: 99%

Acoustic suppressed topological refraction in valley sonic crystals

Wang

Ding

et al. 2022

New J. Phys.

Self Cite

View full text Add to dashboard Cite

We report both experimentally and numerically that an acoustic suppressed topological refraction is realized by two kagome-lattice valley sonic crystals (VSCs). By simply rotating triangle rods in the VSCs, acoustic valley Hall phase transitions can be obtained. In a designed topological waveguide composed of two VSCs with distinct valley topological phases, two types of valley edge states can be observed in the domain wall. Furthermore, the topological waveguide can support a suppressed topological refraction of sound, which arises from the excitation of an acoustic dipole mode at the exit of the domain wall. Such a phenomenon is experimentally demonstrated by scanning topological refractions of the edge states from a zigzag termination, in which the theoretical prediction of a negative refraction almost overlaps with the perpendicular bisector of the dipole mode, and thus it is suppressed totally. Finally, the robustness of the suppressed topological refraction is demonstrated experimentally. Our work can find potential applications in designing the devices of robust directional sound transports and communications.

show abstract

“…To modulate waves in 2D scales, the concept of metasurfaces was proposed in optics [3] based on the generalized Snell's law (GSL) [4]. With the advantage of ultrathin and lightweight compact structure, the acoustic metasurface has also attracted broad attention in the past decade [5][6][7][8][9][10]. By intriguingly designing the functional units, multiple functionalities can be realized, such as abnormal reflection [11,12], negative refraction [13,14], beam focusing [15], vortex sources and perfect absorption [16][17][18][19], and self-bending beams [20].…”

Section: Introductionmentioning

confidence: 99%

Underwater Transmitted Wavefront Manipulation Based on Bubble-Arrayed Acoustic Metasurfaces

Lin²,

Zeng³

et al. 2022

Front. Phys.

View full text Add to dashboard Cite

Manipulating underwater acoustic waves along the prescribed trajectory has great potential for various applications. Traditional metasurfaces for underwater acoustic modulation usually have complex structural designs and are complicated to manufacture. Here, we propose a simple strategy of embedding air bubbles of different sizes inside the polymer to freely manipulate the transmitted underwater acoustic wavefields. The transmitted phase shift covers the entire 2π range by adjusting the diameter of the bubbles. Utilizing the air-bubble array with precisely designed phase profiles, the abnormal refraction, self-bending beams, and bottle beams are univocally demonstrated based on the generalized Snell’s law. Our study can be used for designing waterborne metasurfaces with simple structures to freely manipulate the transmitted wavefronts and inspire lots of applications for underwater explorations.

show abstract

Tunable Topological Refractions in Valley Sonic Crystals With Triple Valley Hall Phase Transitions (Invited Paper)

Cited by 27 publications

References 43 publications

Exceptional Ring by Non-Hermitian Sonic Crystals

Exceptional Ring by Non-Hermitian Sonic Crystals

Acoustic suppressed topological refraction in valley sonic crystals

Underwater Transmitted Wavefront Manipulation Based on Bubble-Arrayed Acoustic Metasurfaces

Contact Info

Product

Resources

About