Observation of topological edge modes in a quasi-periodic acoustic waveguide*

We present a system of acoustic waveguide generated by a simple quasi-periodic patterning without any additional fine-tuning. The system presents topological edge modes. The waveguides are characterized experimentally by standard acoustic measurements, and via a finite element approach utilizing COMSOL Multiphysics. The experimental results and simulations confirm the existence of topological edge modes in these gaps.