Observation of Stable Bimeron Transport Driven by Spoof Surface Acoustic Waves on Chiral Metastructures

TL;DR

This paper demonstrates the creation and stable transport of topological acoustic bimerons using chiral metastructures driven by spoof surface acoustic waves, highlighting their potential for robust information processing.

Contribution

It introduces a novel method to realize and control stable acoustic bimeron transport via engineered chiral metastructures and SSAWs, advancing topological acoustics.

Findings

Successful realization of acoustic meron textures using designed metastructures.

Construction of chiral metastructures enabling 1D and 2D bimeron transport.

Bimeron transport driven by phase-locked SSAWs related to cavity mode handedness.

Abstract

Topological quasiparticles, such as merons and bimerons, are characterized by non-trivial textures that exhibit remarkably robust transport against deformation, offering significant potential for information processing. While these phenomena have been explored in various systems, acoustic realizations remain challenging. Here, we report that acoustic meron topological textures were successfully realized using designed Archimedeanlike square spiral metastructures via the excitation of spoof surface acoustic waves (SSAWs). By applying mirror-symmetric combinatorial operations to the unit structures, we further construct composite chiral metastructures that enable both one-dimensional and two-dimensional stable transport of acoustic bimerons. It is further revealed that bimeron transport originates from the locked opposite phase differences of SSAWs, induced by the handedness of the cavity resonant modes. The intrinsic robustness of the meron textures against structural defects is confirmed through the calculation of their topological charge. Our findings establish stable acoustic bimeron transport as a topologically resilient foundation for future acoustic information processing and storage technologies.