Topological Nodal Charge Density Waves in Weyl Semimetals

We examine a Weyl semimetal system with perfect Fermi surface nesting and a charge density wave. The charge density wave establishes a pairing in the particle-hole channel between Fermi surfaces surrounding Weyl nodes of opposite chirality, resulting in a nontrivial nodal structure in the charge density wave order parameter. This nodal structure requires a description in terms of monopole harmonics, by analogy with previous work on monopole harmonic superconductivity.