  Twisted van der Waals (vdW) heterostructures have recently emerged as an
attractive platform to study tunable correlated electron systems. However, the
quantum mechanical nature of vdW heterostructures makes their theoretical and
experimental exploration laborious and expensive. Here we present a simple
platform to mimic the behavior of twisted vdW heterostructures using acoustic
metamaterials comprising of interconnected air cavities in a steel plate. Our
classical analog of twisted bilayer graphene shows much of the same behavior as
its quantum counterpart, including mode localization at a magic angle of about
1.1 degrees. By tuning the thickness of the interlayer membrane, we reach a
regime of strong interactions more than three times higher than the feasible
range of twisted bilayer graphene under pressure. In this regime, we find the
magic angle as high as 6.01 degrees, corresponding to a far denser array of
localized modes in real space and further increasing their interaction
strength. Our results broaden the capabilities for cross-talk between quantum
mechanics and acoustics, as vdW metamaterials can be used both as simplified
models for exploring quantum systems and as a means for translating interesting
quantum effects into acoustics.
