Collective excitations in Weyl semimetals in the hydrodynamic regime

Understand

The spectrum of collective excitations in Weyl materials is studied by using consistent hydrodynamics.

• The corresponding framework includes the vortical and chiral anomaly effects, as well as the dependence on the separations between the Weyl nodes in energy $b_0$ and momentum $\mathbf{b}$.
• The latter are introduced via the Chern-Simons contributions to the electric current and charge densities in Maxwell's equations.
• It is found that, even in the absence of a background magnetic field, certain collective excitations (e.g.