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

TL;DR

This paper demonstrates the experimental realization of axial-field-induced chiral channels in an acoustic Weyl metamaterial, revealing new ways to observe non-local Weyl orbits and unidirectional bulk transport.

Contribution

It introduces an inhomogeneous potential to simulate axial fields in an acoustic Weyl system, leading to the observation of chiral Landau levels and novel transport phenomena.

Findings

Observation of axial-field-induced chiral Landau levels

Potential for non-local Weyl orbit experiments

Enabling unidirectional bulk transport in acoustic systems

Abstract

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. Here, we provide the experimental characterization of the effect of such an axial field in an acoustic metamaterial. We implement the axial field through an inhomogeneous potential and observe the induced chiral Landau levels. From the metamaterials perspective these chiral channels open the possibility for the observation of non-local Weyl orbits and might enable unidirectional bulk transport in a time-reversal invariant system.