CN115394280A - Underwater phononic crystal based on valley Hall induced topological angular state - Google Patents
Underwater phononic crystal based on valley Hall induced topological angular state Download PDFInfo
- Publication number
- CN115394280A CN115394280A CN202210940051.7A CN202210940051A CN115394280A CN 115394280 A CN115394280 A CN 115394280A CN 202210940051 A CN202210940051 A CN 202210940051A CN 115394280 A CN115394280 A CN 115394280A
- Authority
- CN
- China
- Prior art keywords
- phononic crystal
- scatterer
- topological
- hexagonal structure
- underwater
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/18—Methods or devices for transmitting, conducting or directing sound
- G10K11/26—Sound-focusing or directing, e.g. scanning
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
The invention relates to the technical field of acoustics, and discloses an underwater phononic crystal based on a valley Hall induced topological angular state, wherein the phononic crystal is of a two-dimensional honeycomb hexagonal structure; a plurality of scatterers are rotatably arranged in the hexagonal structure; a central column is also arranged in the center of the hexagonal structure; each scatterer is uniformly distributed around the central column, and the rotating angles formed by each scatterer and the central column are the same. The invention solves the problem that the existing two-dimensional phononic crystal structure device is lack of flexibility of switching and selection, and has the characteristic that the boundary mode related to pseudo-spin has strong robustness to defects.
Description
Technical Field
The invention relates to the technical field of acoustics, in particular to an underwater phononic crystal based on a valley Hall induced topological angular state.
Background
In recent years, the discovery of Quantum Hall Effect (QHE), quantum Spin Hall Effect (QSHE), quantum Anomalous Hall Effect (QAHE), topological Insulator (TI), etc. has attracted more and more attention to abstract topological concepts in mathematics, and has opened up a new chapter for the research of topological insulators in condensed-state physics. The novel topological properties provide great flexibility for manipulating robust edge states, potentially allowing the development of new generations of low-power transistors and electronics, thereby driving advances in information technology. Introducing the concept of topology into classical wave systems such as light waves, mechanical waves and sound waves is a popular field of current research, and can realize edge states protected by topology and a plurality of novel functions.
The topological transmission of the topological insulator is topologically protected. One of the prominent features of topological transmission is that it has the function of immune defect, and the original transmission state can be maintained and hardly generates reflection at the position with defect. Topological states in topological insulators have many novel features, such as: one-way transmission boundary state, no backscatter, etc.
The discovery of the phononic crystal further enriches the research of the topological insulator and develops a wider research field for the topological insulator. In the volume-edge correspondence, the dimension of the boundary state of the phononic crystal of the same dimension is lower than that of the first-order topological insulator. The band gap of the phononic crystal has not only edge states for opening energy gaps, but also zero-dimensional angular states (corner states) or one-dimensional edge states (hinge states) in the opened energy gaps, and the edge states are topologically protected, can stably exist and have strong robustness.
In addition to the two degrees of freedom, charge and spin, solid materials also have a valley degree of freedom. Gu Shizhi the quantum states of the energy extrema in momentum space, the angular momentum of the non-equivalent Gu Chubo function produce opposing magnetic moments, thereby producing the quantum valley hall effect. The valley degree of freedom can be used as a new information carrier, marks discrete energy extreme states in momentum space, widely appears in conventional semiconductors, and in current popular two-dimensional crystal graphene and molybdenum disulfide, and can be used for future electronic device design. In acoustic systems, like spins in spintronics, the valley degree of freedom is called pseudo-spin. The concept of valley states is introduced into phononic crystals, excited directly by an external acoustic field of specific frequencies, which exist as edge states that support topological preservation. The dirac points in the pseudo-spin acoustic topological insulator are mostly generated by high symmetry, the dirac points can be formed by constructing a hexagonal honeycomb lattice structure with special symmetry, and then topological inversion is realized by changing the angle of a scatterer. The vortex-locked valley transportation provides a brand-new sound wave control mode for people, such as rotating control of microparticles, selective excitation of valleys, anti-reflection of boundary turning and the like, and the information processing by utilizing the valley degree of freedom has the advantages of difficulty in information loss, high processing speed, low energy consumption, high integration level, long transmission distance and the like.
The underwater sound wave is used as a longitudinal wave, has no polarization characteristic in the fluid, and has no spin state. The existing acoustic topological isolator mainly studies the propagation of relatively easily obtained sound in air, and the previous study on the acoustic pseudo-spin Hall effect mainly studies a scatterer-dielectric matrix structure and a dielectric plate-hole structure, or adopts a ring airflow design to realize an acoustic topological insulator, and a high-order topological boundary state is connected with a specific corner point or a hinge, so that the flexibility of switching and selection is lacked.
The existing patent has a dual-band acoustic wave beam splitter device based on the valley hall effect, which includes a substrate with a medium of air and a scatterer with a medium of acoustic rigid material, and utilizes a graphene-like honeycomb two-dimensional phononic crystal structure device to simulate the quantum valley hall effect in acoustics, because the phononic crystal primitive cell structure keeps the symmetry of C6, two linear dirac degenerate points exist at the K point in the Brillouin zone at the same time, the energy band structure of the two-dimensional honeycomb phononic crystal is obtained by utilizing commercial simulation software, the symmetry in the phononic crystal is adjusted to obtain the extreme point-valley in the energy band, the extreme point-valley is used as a carrier of information, and then two phononic crystal waveguide structures with different topological states are combined to realize a boundary state with the characteristics of inhibiting backscattering and unidirectional transmission, and the dual-band acoustic wave beam splitter device is realized by utilizing the unidirectionality of the boundary state.
The problem that how to invent a novel phononic crystal which can carry out pure geometric manipulation on an achiral scatterer and realize pseudo spin topological state and high-order topological state is needed to be solved urgently in the technical field is that the existing graphene-like honeycomb two-dimensional phononic crystal structure device lacks flexibility of switching and selecting.
Disclosure of Invention
The invention provides an underwater phononic crystal based on a valley Hall induced topological angular state, aiming at solving the problem that the conventional two-dimensional phononic crystal structure device is lack of flexibility in switching and selection, and the underwater phononic crystal has the characteristic that a boundary mode related to pseudo spin has strong robustness on defects.
In order to realize the purpose of the invention, the technical scheme is as follows:
an underwater phononic crystal based on a valley Hall induced topological angular state is characterized in that the phononic crystal is of a two-dimensional honeycomb hexagonal structure; a plurality of scatterers are rotatably arranged in the hexagonal structure; a central column is also arranged in the center of the hexagonal structure; each scatterer is uniformly distributed around the central column, and the rotating angles formed by each scatterer and the central column are the same.
According to the invention, by designing the two-dimensional honeycomb hexagonal structure and rotatably arranging the plurality of scatterers in the hexagonal structure, pure geometric manipulation of the achiral scatterers is realized, pseudo spin topological state and high-order topological state are realized, and the robustness of the boundary mode related to pseudo spin to defects is improved.
Preferably, the scatterer is a crescent scatterer.
Furthermore, the tooth mouth of the crescent scatterer faces clockwise.
Furthermore, 3 crescent scatterers are rotatably arranged in the hexagonal structure; the 3-month tooth-shaped scatterer is represented by C 3 Symmetry is rotatably disposed about the central post in a hexagonal configuration.
Further, in the initial non-rotated state, the positions of the 3 crescent shaped scatterers in each hexagonal structure correspond to 3 angles of the hexagonal honeycomb cells, respectively.
Furthermore, the rotation angle formed by the scatterer and the central column, i.e. the included angle between the connecting line of the tangent point of the inner arc of the crescent scatterer and the central point of the hexagonal structure and the connecting line of the adjacent vertex and the center of the adjacent hexagonal structure, is marked as θ.
Furthermore, the distance between two opposite sides of the hexagonal structure is a predetermined value and is denoted as a lattice constant, the lattice constant is denoted as a, and the crescent scatterers are formed by stacking two circles with a radius of 0.1 × a and a distance of b between the centers of the circles. The distance between two opposite sides of the hexagonal structure is a preset value and is recorded as a lattice constant, the lattice constant is represented as a, and the crescent scatterers are formed by stacking two circles with the radius of 0.1 × a and the distance between the centers of the circles and b.
Furthermore, the central column is made of steel.
Furthermore, the material of the scatterer is rubber.
Furthermore, the base material of the hexagonal structure is water.
The invention has the following beneficial effects:
according to the invention, by designing the two-dimensional honeycomb hexagonal structure and rotatably arranging the plurality of scatterers in the hexagonal structure, pure geometric manipulation of the achiral scatterers is realized, pseudo spin topological state and high-order topological state are realized, and the robustness of the boundary mode related to pseudo spin to defects is improved. The invention solves the problem that the existing two-dimensional phononic crystal structure device is lack of flexibility in switching and selection.
Drawings
Fig. 1 is a schematic structural diagram of an underwater phononic crystal based on a valley hall induced topological angular state.
FIG. 2 is a first Brillouin zone of an underwater phononic crystal of the present invention based on Valley Hall induced topological angular states.
Fig. 3 is an energy band diagram of the underwater photonic crystal based on the valley hall induced topological angular state when the rotation angle theta of the scatterer is = -4.57 degrees.
Fig. 4 is an energy band diagram of the underwater phononic crystal based on the valley hall induced topological angular state when the rotation angle theta of the scatterer is = -33.4 degrees.
Fig. 5 is an energy band diagram of an underwater phononic crystal based on a valley hall induced topological angular state of the present invention at a rotation angle θ =23 ° of a scatterer.
FIG. 6 is an eigenfrequency diagram of two band gap edges of the underwater photonic crystal at K points corresponding to the photonic crystal at different rotation angles theta based on the valley Hall induced topological angular state.
FIG. 7 is a dispersion curve diagram of underwater phononic crystals based on valley Hall induced topological angular states at different boundary types.
FIG. 8 is an intrinsic acoustic pressure field distribution diagram of an underwater photonic crystal based on valley Hall induced topological angular states under a positive type boundary state according to the present invention.
FIG. 9 is an intrinsic acoustic pressure field distribution diagram of an underwater phononic crystal based on a valley Hall induced topological angular state under a negative boundary state.
FIG. 10 is a finite quadrilateral supercell acoustic pressure field distribution and eigenmode diagram formed by underwater phononic crystals based on valley Hall induced topological angular states.
FIG. 11 is a finite quadrilateral supercell acoustic pressure field distribution diagram containing defects and composed of underwater phononic crystals based on valley Hall induced topological angular states.
Fig. 12 is a schematic diagram of a tiled two-dimensional flexural acoustic waveguide structure composed of topologically non-mediocre and topologically mediocre based underwater phononic crystals of the present invention.
Fig. 13 is a graph of the intrinsic acoustic pressure field of a spliced two-dimensional flexural acoustic waveguide structure composed of an underwater phononic crystal of the present invention based on valley hall induced topological angular states at a frequency of 42kHz with an excitation source of topological indifference and topological indifference.
Detailed Description
The invention is described in detail below with reference to the drawings and the detailed description.
Example 1
As shown in fig. 1, an underwater phononic crystal based on a valley hall induced topological angular state is a two-dimensional honeycomb hexagonal structure; a plurality of scatterers are rotatably arranged in the hexagonal structure; a central column is also arranged in the center of the hexagonal structure; each scatterer is uniformly distributed around the central column, and the rotating angles formed by each scatterer and the central column are the same.
In this embodiment, COMSOL Multiphysics software based on a finite element method is used to simulate the numerical value of the phononic crystal in the present invention, and an energy band diagram of an original cell of the phononic crystal is calculated to reflect two-dimensional crystal properties, a periodic boundary condition is applied to a boundary corresponding to the original cell, and the phononic crystal may have different symmetries by rotating a scatterer around the center.
Example 2
As shown in fig. 1, an underwater phononic crystal based on a valley hall induced topological angular state is a two-dimensional honeycomb hexagonal structure; a plurality of scatterers are rotatably arranged in the hexagonal structure; a central column is also arranged in the center of the hexagonal structure; each scatterer is uniformly distributed around the central column, and the rotating angles formed by each scatterer and the central column are the same.
In a specific embodiment, the scatterer is a crescent-shaped scatterer.
In one embodiment, the mouth of the crescent-shaped diffuser faces clockwise.
In one specific embodiment, 3 crescent-shaped scatterers are rotatably arranged in the hexagonal structure; the 3-month tooth-shaped scatterer is represented by C 3 Symmetry is rotatably disposed about the central post in a hexagonal configuration.
In this embodiment, the lattice constant of the phononic crystal is a =2.1cm, and the crescent scatterers are formed by stacking two circles with a radius of 0.1 × a at a staggered distance from the center of the circle to the center of the circle by b.
In one embodiment, the 3 crescent shaped scatterers in each hexagonal structure are positioned at 3 corners of the hexagonal honeycomb cells in the initial non-rotated state.
In a specific embodiment, the rotation angle formed by the scatterer and the central column is an included angle, which is denoted as θ, between a connection line between an tangent point of an inner arc of the crescent scatterer and a central point of the hexagonal structure and a connection line between adjacent vertexes and centers of adjacent hexagonal structures.
In one embodiment, the distance between two opposite sides of the hexagonal structure is a predetermined value, denoted as a lattice constant, which is denoted as a, and the crescent scatterers are formed by stacking two circles with a radius of 0.1 × a at a distance of b from the center of the circle.
In one embodiment, the material of the central column is steel.
In a specific embodiment, the material of the scatterer is rubber.
In one embodiment, the hexagonal structure is water.
In this embodiment, the crescent scatterers are made of soft rubber, and the central steel column is a circle with a radius of 0.1 × a.
In this embodiment, the density ρ of the soft rubber 1 ＝1000kg/m 3 Speed of sound c 1 =489.9m/s; density of steel = ρ 2 ：8000kg/m 3 Speed of sound c 2 =5000m/s; for water, ρ 0 ＝1000kg/m 3 ，c 0 ＝1482.9m/s。
As shown in fig. 2, the brillouin zone of the primitive cell in the initial non-rotation state can obtain the corresponding dispersion relation through the brillouin zone of the primitive cell; the dispersion relationship is shown in fig. 3, 4, and 5, where the abscissa represents the brillouin zone, the ordinate represents the characteristic frequency, and the line is the energy band.
As shown in fig. 3, when θ = -4.57 °, it can be seen that at a frequency of 42.9KHz, a coincidentally degenerate dirac point appears at the high symmetry point K of the brillouin zone.
In one embodiment, rotating 3 crescent shaped scatterers around the center post may produce different crystal symmetries.
In this embodiment, the scatterer is rotated clockwise by 33.4 ° and counterclockwise by 23 °, and the counterclockwise rotation is changed to positive, so as to obtain the phononic crystal a and the phononic crystal B, respectively. The dispersion relationship between crystal a and crystal B is shown in fig. 4 and 5. Crystal a and crystal B correspond to phonon crystals in topologically non-mediocre and topologically mediocre states, respectively. For the phonon crystal A, a Dirac point is opened to form a band gap with the bandwidth of about 4.1KHz, and a valley Hall state is generated; for the phonon crystal B, the dirac point is also opened, so that in the process of rotating from θ =23 ° to θ = -33.4 °, two times of Gu Huoer phase changes continuously occur, the acoustic Gu Yan spin state of the phase changes shows similar opposite chirality with the electron valley state, and the dirac point opening-closing-opening process is generated at the K point of the high symmetry point of the brillouin zone, which corresponds to fig. 6.
In this embodiment, the Gu Benzheng acoustic vortices all use the cell center as the vortex center, where the vortex center direction of the p-state is clockwise and the q + state is counterclockwise, so that the corresponding electron spin state can be simulated. Wherein, +, -represents the vortex acoustic energy flow counterclockwise and clockwise around the center point, respectively.
In the embodiment, considering the second band gap, for the rotation angle θ with opposite signs, the two photonic crystals AB and AB have different topological properties, although the pressure field distributions of the two eigenstates at the K point also form the band gap, combining the eigen-acoustic pressure field and the vortex distribution characteristics, the corresponding valley eigenstate has inversion, which indicates that the energy band has topological inversion, and the effective masses m near the corresponding dirac cone have opposite signs, that is, m is m (A) ＝-m (B) The valleys Chen Shu of the two kinds of phononic crystals have different valley hall phases, and valley topology transmission can be achieved. C of phononic crystal 3 The symmetry satisfies the symmetry of the pseudo-time reversal operator, so that the acoustic quantum spin Hall effect can be realized.
In this embodiment, the crescent scatterers satisfy spatial rotational symmetry, and on a boundary of a specified type, a topological boundary state excited by a specific valley will propagate in a fixed direction. And splicing and combining the topological water-based phononic crystals with different rotation angles, and respectively defining different types of boundaries as a positive boundary and a negative boundary.
In this embodiment, the valley hall waveguide dispersion relationship of the spliced structure obtained after splicing and combining is shown in fig. 7, where the abscissa is the wave vector k direction and the ordinate is the eigenfrequency. In the figure, the dotted line in the band gap of the bulk band represents the boundary state of boundary transmission, and the energy band at which the A, B point is located represents the topological boundary state of transmission along the negative and positive boundaries, respectively, and the group velocities of the two are opposite. Topological boundary states of the phononic crystal at the interface in the topologically mediocre and non-mediocre states are shown in fig. 8 and 9.
In this embodiment, two-dimensional phononic crystals of topological mediocre and non-mediocre structures are spliced together, with an infinite period in the y direction, it can be seen that the sound field energy is localized only at the splicing boundary, the sound pressure of the eigen-state of the sound pressure is localized at the boundary, i.e., the edge state, and the edge state appears in the band gap of the volume state, and the boundary state connects the volume states. The formation of the boundary state comes from the change of the topological valleys Chen Shu of different topological structures on two sides of the boundary; the disturbance of the phononic crystal A and the phononic crystal B respectively satisfies delta p A <0 and Δ p B >0, where Δ p represents the geometric perturbation, for a negative boundary, since the valley Chen Shu changes to at K' point
And will transmit ac in the opposite direction at point K (K‘) ＝1。
As can be seen from this embodiment, when the rotation angle of the scatterer is θ = -33.4 °, the primitive cell of the phononic crystal is a topological non-trivial structure; in this embodiment, a finite acoustic structure is constructed using protocells of topologically non-mediocre nature. Verifying the robustness of the parallelogram supercell, composing the topological non-plain phononic crystal A into a 10 × 10 parallelogram phononic crystal supercell, and calculating the intrinsic mode condition of the parallelogram phononic crystal supercell within the forbidden band range; as shown in fig. 10, in the acoustic pressure eigen field with the frequency of 44.7kHz angular state, the eigen frequency can be found to exist in the complete band gap, and by observing the acoustic pressure eigen field, one-dimensional boundary state and zero-dimensional angular state can be found, and the shading in the figure represents the forbidden band range. The finite phonon crystal supercell generates topological boundary states and topological angular states in a forbidden band range, and a stable low-dimensional angular point or hinge state appears in a high-order topological insulator edge gap. The angular mode can be clearly seen from the intrinsic field of sound pressure, and for the non-mediocre supercell with the composition of the phononic crystal A, the energy of the sound field is obviously concentrated at the lower left corner, and the sound pressure intensity at other positions is almost zero. The sound pressure eigenfield corresponding to the eigenfrequency outside the band gap is a bulk mode, and the sound pressure of the bulk mode is distributed on the whole limited acoustic structure.
In the embodiment, the topological boundary state is not affected by defects, whether the boundary is a curved boundary or the boundary has defects such as holes and disorder, the topological protected boundary state can bypass the defects and has almost no reflection, so the robustness is strong. A point defect is a defect that deviates from the normal arrangement of crystal structure in microscopic regions on or near the junction, and is the simplest crystal defect, such as vacancies, interstitial atoms, impurity atoms, etc., all of which are point defects, also referred to as zero-dimensional defects. In the following, we verify that in the present phononic crystal, different topologically protected angular states of the pseudo spin state are still stable in the vacancy defect type.
Example 3
More specifically, in the present embodiment, the valley topology sound pressure amplitude distribution generated by acoustic excitation is shown in fig. 11, in which a point sound source indicated by an arrow is located at any point on the phononic crystal interface, and the frequency of the excited sound wave is 44.7kHz. FIG. 10 shows that the finite crystal structure can support valley Hall topology acoustic transmission well when the valley topology phononic crystal is defect free; as in fig. 11, the acoustic source excitation can still bypass the vacancy defect to the corner points of the finite quadrilateral structure composed of the phononic crystal, and, corresponding to fig. 10, the acoustic source excitation can still bypass the vacancy defect to the corner points of the finite quadrilateral structure composed of the phononic crystal,
the flat-to-non-flat boundary corresponds to a negative boundary, and the valley Chen Shu changes to Δ C at the K' point (K‘) = 1, energy flow rotates clockwise, whereas at the non-mediocre boundary the opposite is true, the acoustic pressure field is concentrated mainly at the topologically mediocre and non-mediocre boundaries, and energy decays rapidly as it travels from the interface of the two different crystal lattices of phononic crystal a and phononic crystal B to the left and right. Can support due to the limited structure proposedTopological boundary states, we can therefore exploit this unique property to realize new functional waveguide devices.
In the embodiment, a two-dimensional bending acoustic waveguide structure is formed by splicing topological non-flat lattices and topological flat lattices, the structure is formed by splicing a phononic crystal A and a topological flat phononic crystal B, the interface comprises topological flat and topological non-flat primitive cells, the upper side and the lower side of a dotted line and a solid line are respectively the topological flat lattice and the topological non-flat lattice, and the interface trend is a bending curve. As shown in fig. 12, the dotted line and the solid line are respectively two different types of splicing interfaces, the solid line is a zigzag interface, and the dotted line is an armchair interface, and the two different types of lattices are spliced to construct a directional waveguide structure.
In this embodiment, a point sound source is placed at the left end of the two-dimensional finite waveguide structure, i.e., at the splicing interface of the phonon crystal a and the phonon crystal B, for intrinsic field excitation. Fig. 13 is an excitation sound pressure field diagram of the two-dimensional bending acoustic waveguide structure at an excitation source frequency of 42kHz, and from the sound pressure field distribution, it can be found that, due to the existence of a boundary state protected by topology at the interface of non-plain and plain splicing, even if the interface of splicing of the phonon crystal a and the phonon crystal B has a bending type shape, an acoustic wave can propagate forward along the interface, and back scattering is effectively suppressed. On one hand, the method shows that even if some uncontrollable bending defects exist in the waveguide structure, the edge state can still bypass the defects and propagate to the right side of the waveguide, so that the Gu Tapu acoustic waveguide is shown to have good robustness; on the other hand, since the photonic crystal structure has high-transmittance back-scattering-free acoustic transmission, an acoustic waveguide transmission device and material with specific functionality can be designed and constructed according to the propagation characteristics of the photonic crystal waveguide and by using the interface state protected by topology.
According to the invention, by designing the two-dimensional honeycomb hexagonal structure and rotatably arranging the plurality of scatterers in the hexagonal structure, pure geometric manipulation of the achiral scatterers is realized, a pseudo spin topological state and a high-order topological state are realized, and the robustness of a boundary mode related to pseudo spin on defects is improved. The invention theoretically designs a high-order topological angular state with selectivity by adopting common materials. The angular point state shows different geometric angles due to different valley selections, shows topology switching and valley point selectivity, provides a theoretical model for interaction among a high-order topology insulator, a valley selection angular state and a higher-order valley degree of freedom, and is beneficial to improving the flexibility of the selective angular point. The selective and robust underwater acoustic topological transmission is beneficial to realizing acoustic lossless devices such as topological switch, energy capture and the like. The invention solves the problem that the existing two-dimensional phononic crystal structure device is lack of flexibility in switching and selection.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.
Claims (10)
1. An underwater phononic crystal based on valley Hall induced topological angular state is characterized in that: the phononic crystal is of a two-dimensional honeycomb hexagonal structure; a plurality of scatterers are rotatably arranged in the hexagonal structure; a central column is also arranged in the center of the hexagonal structure; each scatterer is uniformly distributed around the central column, and the rotating angles formed by each scatterer and the central column are the same.
2. The Gu Huoer-based underwater phononic crystal of inducing topological angular states of claim 1, wherein: the scatterer is a crescent scatterer.
3. The Gu Huoer-based underwater phononic crystal of inducing topological angular states of claim 2, wherein: the tooth mouth of the crescent scatterer faces clockwise.
4. The Gu Huoer-based underwater phononic crystal of induced topological angular states of claim 3, wherein: the hexagonal structure is rotatableIs provided with 3 crescent scatterers; the 3-month tooth-shaped scatterer is represented by C 3 Symmetry is rotatably disposed about the central post in a hexagonal configuration.
5. The Gu Huoer-based underwater phononic crystal of claim 4 for inducing topological angular states, wherein: in the initial non-rotated state, the positions of the 3 crescent shaped scatterers in each hexagonal structure correspond to 3 angles of the hexagonal honeycomb cells, respectively.
6. The Gu Huoer-based underwater phononic crystal of induced topological angular states of claim 4, wherein: the rotation angle formed by the scatterer and the central column, namely the included angle between the connecting line of the tangent point of the inner arc of the crescent scatterer and the central point of the hexagonal structure and the connecting line of the adjacent vertex and the center of the adjacent hexagonal structure is marked as theta.
7. The Gu Huoer-based underwater phononic crystal of claim 4 for inducing topological angular states, wherein: the distance between two opposite sides of the hexagonal structure is a preset value and is recorded as a lattice constant, the lattice constant is represented as a, and the crescent scatterers are formed by stacking two circles with the radius of 0.1 × a and the distance between the centers of the circles and b.
8. The Gu Huoer-based underwater phononic crystal of inducing topological angular states of claim 1, wherein: the central column is made of steel.
9. The Gu Huoer-based underwater phononic crystal of inducing topological angular states of claim 1, wherein: the scatterer is made of rubber.
10. The Gu Huoer-based underwater phononic crystal of inducing topological angular states of claim 1, wherein: the base material of the hexagonal structure is water.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210940051.7A CN115394280A (en) | 2022-08-05 | 2022-08-05 | Underwater phononic crystal based on valley Hall induced topological angular state |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210940051.7A CN115394280A (en) | 2022-08-05 | 2022-08-05 | Underwater phononic crystal based on valley Hall induced topological angular state |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115394280A true CN115394280A (en) | 2022-11-25 |
Family
ID=84119660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210940051.7A Pending CN115394280A (en) | 2022-08-05 | 2022-08-05 | Underwater phononic crystal based on valley Hall induced topological angular state |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115394280A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116318034A (en) * | 2023-03-22 | 2023-06-23 | 北京深谋科技有限公司 | Surface acoustic wave device with topology transport function and regulation and control method and application thereof |
-
2022
- 2022-08-05 CN CN202210940051.7A patent/CN115394280A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116318034A (en) * | 2023-03-22 | 2023-06-23 | 北京深谋科技有限公司 | Surface acoustic wave device with topology transport function and regulation and control method and application thereof |
| CN116318034B (en) * | 2023-03-22 | 2023-10-27 | 北京深谋科技有限公司 | Surface acoustic wave device with topology transport function and regulation and control method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Chen et al. | Tunable topological phononic crystals | |
| Du et al. | Optimal quantum valley Hall insulators by rationally engineering Berry curvature and band structure | |
| He et al. | Parity-time electromagnetic diodes in a two-dimensional nonreciprocal photonic crystal | |
| Yuan et al. | Bound states in the continuum on periodic structures surrounded by strong resonances | |
| Xie et al. | Acoustic topological transport and refraction in a Kekulé lattice | |
| Yudistira et al. | Non-radiative complete surface acoustic wave bandgap for finite-depth holey phononic crystal in lithium niobate | |
| CN115394280A (en) | Underwater phononic crystal based on valley Hall induced topological angular state | |
| CN111965736B (en) | Topological photonic crystal composite structure for realizing optical wave unidirectional transmission based on energy band inversion | |
| CN113470611B (en) | Underwater acoustic topological insulator with simultaneous pseudo-spin topological state and higher-order topological state | |
| Chen et al. | Valley Hall elastic topological insulator with large Chern numbers | |
| Xu et al. | Angular selection of incident waves by photonic crystals with position-varying Dirac points at the Brillouin zone boundary | |
| WO2012126249A1 (en) | Electromagnetic wave-deflecting metamaterial | |
| CN114967188A (en) | Two-dimensional hexagonal lattice phononic crystal and waveguide structure thereof | |
| CN115273792A (en) | Acoustic device based on phononic crystal theory | |
| Song et al. | Switchable directional sound emission with improved field confinement based on topological insulators | |
| Zhou et al. | On-chip unidirectional waveguiding for surface acoustic waves along a defect line in a triangular lattice | |
| Han et al. | Nonlocal Acoustic Moiré Hyperbolic Metasurfaces | |
| Russell et al. | Bound modes of two-dimensional photonic crystal waveguides | |
| Stelson et al. | Photonic crystal properties of self-assembled Archimedean tilings | |
| Li et al. | Higher-order topological states in dual-band valley sonic crystals | |
| Jiang et al. | Acoustic valley edge states in a graphene-like system with sub-wavelength resonator | |
| Tong et al. | Directional acoustic emission via topological insulators based on cavity-channel networks | |
| CN114994808A (en) | Energy valley photonic crystal structure and photonic crystal waveguide structure based on liquid crystal material | |
| Tang et al. | Acoustic energy transport based on the local state characteristics of a symmetric interface | |
| Hiett et al. | Photonic band gaps in 12-fold symmetric quasicrystals |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |