Anisotropic optical response of dense quark matter under rotation: compact stars as cosmic polarizers

Quantum vortices in the color-flavor locked phase of QCD have bosonic degrees of freedom, called the orientational zero modes, localized on them. We show that the orientational zero modes are electromagnetically charged. As a result, a vortex in the color-flavor locked phase nontrivially interacts with photons. We show that a lattice of vortices acts as a polarizer of photons with wavelengths larger than some critical length.