Recently, the topological physics in artificial crystals for classical waves has become an emerging research area. In this Letter, we propose a unique bilayer design of sonic that are constructed by two layers coupled hexagonal array triangular scatterers. Assisted additional layer degree freedom, rich phase diagram is achieved simply rotating scatterers both layers. Under unified theoretical framework, kinds valley-projected acoustic insulators distinguished analytically, i.e., layer-mixed...

Quantum spin Hall (QSH) effect is promising for achieving dissipationless transport devices which can be achieved only at extremely low temperature presently. The research new large-gap QSH insulators critical their realistic applications room temperature. Based on first-principles calculations, we propose a insulator with sizable bulk gap as large ∼0.22 eV in stanene film functionalized the organic molecule ethynyl (SnC2H), whose topological electronic properties are highly tunable by...

In the present work, we experimentally implement, numerically compute with, and theoretically analyze a configuration in form of single column woodpile periodic structure. Our main finding is that Hertzian, locally resonant, lattice offers test bed for formation genuinely traveling waves composed strongly localized solitary wave on top small amplitude oscillatory tail. This type wave, called nanopteron, not only motivated numerically, but also visualized by means laser Doppler vibrometer....

Abstract Three-dimensional topological nodal lines, the touching curves of two bands in momentum space, which give rise to drumhead surface states, provide an opportunity explore a variety exotic phenomena. However, solid evidence for flat state remains elusive. In this paper, we report realization three-dimensional line dispersions and states phononic crystal. Profiting from its macroscopic nature, crystal permits flexible accurate fabrication materials with ring-like lines states. Phononic...

Two-dimensional dumbbell (DB) stanene has been proposed as a promising candidate material for realizing quantum spin Hall effect (QSHE) by Tang et al [P. Tang, P. Chen, W. Cao, H. Huang, S. Cahangirov, L. Xian, Y. Xu, C. Zhang, Duan, A. Rubio. Phys. Rev. B, 90, 121408 (2014)]. However, the small bulk-gap limits its possible applications at room temperature. Based on first-principles calculations, we predict that band gap can be enhanced to 148 meV under methyl-functionalization, which...

Abstract Discovery of two-dimensional (2D) topological insulator such as group-V films initiates challenges in exploring exotic quantum states low dimensions. Here, we perform first-principles calculations to study the geometric and electronic properties 2D arsenene monolayer with hydrogenation (HAsH). We predict a new σ-type Dirac cone related p x,y orbitals As atoms HAsH, dependent on in-plane tensile strain. Noticeably, spin-orbit coupling (SOC) opens spin Hall (QSH) gap 193 meV at cone....

Recently, the topological states in electric circuits have attracted a great deal of attention, and they formed basis field so-called topoelectrical circuits. We realize second-order circuit with capacitors inductors, we observe corner that exist bulk gap, continuum modes, dependence on shapes by measuring resonance peaks impedance. More importantly, broaden to non-Hermitian region adding resistors. Interestingly, non-Hermiticity tunes amplitude impedance; however, it has no effect...

By applying an out-of-phase actuation at the boundaries of a uniform chain granular particles, we demonstrate experimentally that time-periodic and spatially localized structures with nonzero background (so-called dark breathers) emerge for wide range parameter values initial conditions. We remarkable control over number breathers within multibreather pattern can be "dialed in" by varying frequency or amplitude actuation. The (or amplitude) where transition between different states occurs...

We present an active, purely mechanical stress wave isolator that consists of short cylindrical particles arranged in a helical architecture. This phononic structure allows us to change inter-particle stiffness dynamically by controlling the contact angles cylinders. use torsional travelling waves control angles, thereby imposing desired spatio-temporal variation crystal along longitudinal direction. Such excitation is form parametric pumping system, which results breakage time-reversal...

Abstract Quantum spin Hall (QSH) insulators feature edge states that topologically protected from backscattering. However, the major obstacles to application for QSH effect are lack of suitable with a large bulk gap. Based on first-principles calculations, we predict class large-gap in ethynyl-derivative functionalized stanene (SnC 2 X; X = H, F, Cl, Br, I), allowing viable applications at room temperature. Noticeably, SnC Br and I gap ~0.2 eV, while H F can be transformed into insulator...

Acoustic valley materials, usually constructed in a hexagonal lattice, provide an additional degree of freedom (so-called valleys their band structures) for manipulating sound waves. This study realizes such material $s\phantom{\rule{0}{0ex}}q\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}e$ which the topological transport and negative refraction acoustic kink waves are observed experiment. At intersection channels, counterintuitive phenomenon...

Acoustic waves can act as tweezers to trap and rotate particles without contact, which have promising application in the manipulation of tissues living cells. Here, we report a realization acoustic motor. The device is fabricated on silicon chip scaled manipulate transfers incident plane ultrasonic into vortex beam, traps center exerts torque simultaneously. As an illustration, put shrimp eggs inside observe driving rotation. rotation frequency egg be easily controlled, its relationship...

The physical realization of pseudomagnetic fields (PMFs) is an engaging frontier research. As in graphene, elastic PMF can be realized by the structural modulations Dirac materials. We show that, presence PMFs, conical dispersions split into Landau levels, and modes robustly propagate along edges, similar to quantum Hall edge transports. In particular, we reveal unique snake states on-chip heterostructure with two opposite PMFs. flexibility micromanufacture silicon chips low loss waves...

Abstract Optical and acoustic tweezers, despite operating on different physical principles, offer non-contact manipulation of microscopic mesoscopic objects, making them essential in fields like cell biology, medicine, nanotechnology. The advantages limitations optical complement each other, particularly terms trapping size, force intensity, flexibility. We use photoacoustic effects to generate localized Lamb wave capable mapping arbitrary laser pattern shapes. By using waves vibrate the...

Ideal Weyl points, which are related by symmetry and thus reside at the same frequency, could promote deep development utilization of physics. Although ideal type-I points have been achieved in photonic crystals, type-II with tilted cone-like band dispersions, still beyond discovery. Here we realize minimal number three-dimensional layer-stacked phononic demonstrate topological phase transition from semimetal to valley insulators two distinct types. The Fermi-arc surface states exist on...

Bound states in the continuum (BICs) have received increasing attention from researchers because of their potential applications photonic crystal fibers, as well lasing, sensing, and surface acoustic wave devices. BICs been experimentally observed resonators, slabs, optical waveguides. Herein, we constructed a topological inductor–capacitor (LC) circuit to observe BICs; consists two identical LC Su–Schrieffer–Heeger chains coupled using middle chain with capacitors. In addition, BIC...