WebJun 9, 2024 · Considering the increasing order of the approximants, we approach nearly isotropic effective speeds of sound and isotropic acoustical activity. The latter is directly … WebJun 22, 2024 · chiral symmetry requires the acoustic wave to go through an impedance Z v and reach an absolute soft-wall boundary , oth- erwise the hard boundaries with Z =∞ will result in 0 = 0.
Chiral Seismic Attenuation with Acoustic Metamaterials
The above physics can be extended to the 3D metamaterial with the unit cell shown in Fig. 3a. The unit cell consists of three chiral resonators mutually connected with tubes, as shown in Fig. 3b. The numerically calculated band structure of the metamaterial is shown in Fig. 3c. The lowest three bands derive … See more The longitudinal nature of airborne sound (\({{{{{\boldsymbol{\nabla }}}}}}\times {{{{{\bf{v}}}}}}=0\)) dictates that the velocity field v aligns with the direction of wave vector k in general. … See more The SOIs of transverse waves can also happen in real space. One intriguing phenomenon induced by such SOIs is the spin-dependent vortex generation in the scattering of subwavelength particles, which leads to the … See more The transverse sound near the \(\Gamma\) point in Fig. 3c can be described by an effective Hamiltonian \(H=-v{{{{{\bf{S}}}}}}\cdot {{{{{\bf{k}}}}}}\) with S being the spin-1 operator defined as \({({S}_{i})}_{{jk}}= … See more WebJan 6, 2024 · The chiral edge states in graphene have been experimentally observed by harnessing the QH effect with an external magnetic field ( 7 ). Without requiring an external magnetic field, the graphene chiral edge states can also be realized by harnessing the QSH effect ( 8 ). However, because of the weak spin-orbit interaction, experimental ... fun stocking stuffer ideas for teens
Wave Propagation in Auxetic Tetrachiral Honeycombs
WebDec 13, 2024 · The scenario is akin to realizing nonreciprocal sound propagation in an elastic metamaterial via spatiotemporally modulating the stiffness [67–74], where the Brillouin-scattering process will lead to chiral acoustic wave transport. In this work we first derive the dispersion relation of the metamaterial waveguide by employing the … WebOct 12, 2015 · with f the frequency of the sound wave, c 1 the sound speed in the medium surrounding the SPP and c 2 the sound speed in the material that constitutes the SPP. A normally incident axisymmetric acoustic wave thus emerges from the SPP with a pressure field having an azimuthal dependence of the form i.e. an acoustic vortex with topological … WebApr 1, 2024 · Such a material property has recently been realized in elastic wave systems [24][25] [26] [27] but is so far missing in acoustic wave systems. We theoretically and experimentally demonstrate two ... fun stocking stuffer ideas for adults