Axial-field-induced chiral channels in an acoustic Weyl system

Understand

Condensed-matter and other engineered systems, such as cold atoms, photonic, or phononic metamaterials, have proven to be versatile platforms for the observation of low-energy counterparts of elementary particles from relativistic field theories.

• These include the celebrated Majorana modes, as well as Dirac and Weyl fermions.
• An intriguing feature of the Weyl equation is the chiral symmetry, where the two chiral sectors have an independent gauge freedom.
• While this freedom leads to a quantum anomaly, there is no corresponding axial background field coupling differently to opposite chiralities in quantum electrodynamics.