Twisted Bilayer Kagome Acoustic Metamaterials

Quantum twistronics–the use of van der Waals heterostructures to create moire systems with novel electronic properties–has opened a vast parameter space of materials and assembly techniques that overwhelms the capabilities of direct exploration. Acoustic metamaterials have emerged as solutions to prototype their laborious quantum counterparts, and twisted bilayer graphene has already been successfully translated into the field of acoustics [1]. Here we reproduce similar acoustic metamaterial analogs of kagome twisted bilayers comprised of interconnected air cavities and thin interlayer membranes. Using COMSOL Multiphysics we accurately mimic both the flat band systems and real space modes of kagome twisted bilayers, and the easily tunable interlayer coupling of our metamaterials allows us to increase our magic angle to allow more computationally tractable supercell sizes. Our work demonstrates a macroscopic, continuously controllable platform for investigating twistronics beyond graphene.

[1] S Minhal Gardezi et al, 2D Materials 8, 031002 (2021)