  Moir\'e lattices which consist of parallel but staggered periodic lattices
have been extensively explored due to their salient physical properties, such
as van Hove singularities[1, 2], commensurable incommensurable transitions[3],
non-Abelian gauge potentials[4], fractional quantum Hall effects[5-7], van der
Waals interfaces[8, 9] and unconventional superconductivity[10, 11]. However,
there are limited demonstrations of such concepts for classical wave systems.
Here, we realized gauge fields in one-dimensional Moir\'e phononic lattices
consisting of two superimposed periodic patterns which mismatched with each
other along one direction. Benefiting from gauge fields, we generated Landau
level flat bands near the Dirac cone and experimentally measured their spatial
localization in pressure-field distributions. Then, by mismatching lattices
along both directions, we constructed two-dimensional Moir\'e phononic lattices
with van der Waals interfaces. We found that acoustic waves efficiently
transported along van der Waals interfaces behaving as metallic networks. As
mismatched lattices are well-controllable, our study offers a novel path to
manipulate sound waves which are inaccessible in traditional periodic acoustic
systems, and can be easily extended to mechanics, optics, electromagnetics and
electronics.
