Universal chiral magnetic effect in the vortex lattice of a Weyl superconductor

Abstract

It was shown recently that Weyl fermions in a superconducting vortex lattice can condense into Landau levels. Here we study the chiral magnetic effect in the lowest Landau level: The appearance of an equilibrium current $I$ along the lines of magnetic flux $\\Phi$, due to an imbalance between Weyl fermions of opposite chirality. A universal contribution $dI/d\\Phi=(e/h)^2\\mu$ (at equilibrium chemical potential $\\mu$ relative to the Weyl point) appears when quasiparticles of one of the two chiralities are confined in vortex cores. The confined states are charge-neutral Majorana fermions.