Acoustic topological insulator

Abstract

An acoustic topological insulator structure 1 is composed of a regular hexagon flat plate 2 and regular triangular prisms 3, the regular triangular prisms 3 are periodically arranged on the regular hexagon flat plate 2 according to triangular lattices, the regular triangular prisms 3 are divided to four parts, a left upper part 7 and a right lower part 8 rotate for 30 DEG in a clockwise mode, anda left lower part 9 and a right upper part 10 rotate for 30 DEG in an anticlockwise mode. The regular triangular prisms 3 of the acoustic topological insulator left rotate for 30 DEG to 0 DEG and thenright rotate for 30 DEG, the band gaps between double-degeneration energy bands are decreased gradually, a double-degeneration Dirac point is finally formed through integration, the double-degeneration Dirac point is then opened, and becoming larger gradually along with increasing of the rotating angle is achieved. When the double-degeneration energy band of the acoustic topological insulator isopened, closed and then re-opened, insulator energy band inversion and topological phase transformation can be completed, and pseudo-rotation effects are realized. The acoustic topological insulator uses the pseudo-rotation effects to realize acoustic topological robust unidirectional transmission, and a prototype device such as an acoustic splitter 1 is designed.

Description

technical field [0001] The invention relates to the accidental degenerate double Dirac point of the phonon crystal, the pseudo-rotation effect of the phonon crystal, sound propagation control and noise reduction and sound insulation technology, and in particular to an acoustic topological insulator based on a triangular lattice. Background technique [0002] The nature of vibration and noise is not only an important index to measure the comfort of people's daily work and living environment, but also an important technical index to measure the comprehensive performance of aircraft, passenger cars, machine tools and other large mechanical equipment. It is also important in the field of military defense. meaning. The study of phononic crystals opens a new chapter for artificially manipulating wave propagation in elastic media and structures. According to the Bloch theory of periodic structures ω(π / a)=ω(-π / a), the energy bands of ordinary acoustic metamaterials are continuous a...

AI Technical Summary

Problems solved by technology

However, no matter it is the air flow circulation or the gyroscope rotation, it is difficult to control the synchronous and coordinated work. Any potential external disturbance may cause changes in the air flow state and rotational motion, thereby destroying the one-way edge state effect of the acoustic metamaterial.

In addition, the air flow and the movement of the gyroscope will generate inherent loss and noise during the sound wave propagation process, which will seriously affect its engineering application value

Images