Topological acoustic directional transmission device and preparation method thereof

Abstract

The invention discloses a topological acoustic directional transmission device and a preparation method thereof. The device has a broadband characteristic, can generate a pseudo-spin state in a broadband range, and guarantees unidirectional transmission of rotating sound waves along an interface in the broadband range. The topological acoustic directional transmission device needs to be realized by a special cell element, an energy band structure of an initial cell element needs to present quadruple degenerate double-Dirac points, and the double-Delay points can be broken to form a band gap through geometric adjustment of the structure. The sound pressure field distribution near a band gap presents a symmetrical form similar to an electron orbit, and the average sound intensity rotates clockwise or anticlockwise, so that effective acoustic pseudo-spin dipoles and quadrupoles different from a traditional acoustic multi-pole mode are generated. The method has the advantages that the defects of experience design are overcome, and the function and frequency of a topological structure can be designed at will. The broadband topology directional transmission characteristic is achieved, and the relative bandwidth reaches 30.5%. The device has a huge application prospect in high-performance waveguide, energy transmission, noise control and sound integration.

Description

technical field [0001] The invention relates to the technical field of acoustic metamaterials, in particular to a topological acoustic directional transmission device and a preparation method thereof. Background technique [0002] Topological insulator (Topological Insulator) is a new state of matter newly discovered in the field of condensed matter physics. Scientists have discovered that in addition to real space, the dispersion relations in the inverted space of crystals can also have different topological properties, and then proposed a new class of materials with topological non-trivial properties. They are different from traditional metal and insulator materials. The most intuitive property is that the interior is an insulator and does not conduct electricity, but the surface can conduct electricity. Topological insulators are also closely related to research hotspots in recent years, such as quantum Hall effect and quantum spin Hall effect. They have in common that t...

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Problems solved by technology

[0003] For sound waves, it is extremely difficult to realize the topological state of air sound and water sound, because they are longitudinal waves with zero spin, and do not have magnetoacoustic effect, and cannot break the time reversal symmetry by applying an external magnetic field

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