Weyl fermions and fragile topology in acoustic meta-materials

Topological band theory provides us with a powerful design-principle for metamaterials that control how waves propagate in space. These metamaterials are ideal to investigate novel phenomena difficult to observe in other platforms. In particular, I will present how artificial gauge fields lead to the appearance of chiral Landau levels in neutral Weyl systems and crystalline symmetries to novel fragile topological states in an acoustic super-structure.