  The axion particle is the outcome of the proposed Peccei-Quinn mechanism for
solving the strong CP problem. Axion is also a popular dark matter candidate.
Thus there is an increased interest in establishing its existence. Axions
couple to two photons and most experiments search for the transition of an
axion into a photon, in the presence of a magnetic field. In our study we
examine the coupling of the axion into a pair of entangled photons. The
presence of a magnetic field changes the polarization correlations of the
entagled photons, thus offering an unambiguous signature for axion existence
