Faraday effect with Polarization Entangled Photons in iron dope CdMnTe

we report for the first time to our knowledge on the polarization rotation as function of magnetic field for entangled photons in Iron dope Cd0.85Mn0.15Te:Fe crystal. These results open the door for the study of magneto-optics effects, and absorption and reflection spectroscopy in condense matter systems with single photons. We show that the predictions of quantum mechanics are in excellent agreement with the experimental results, but that the underlying physics and universality of accepted quantities like the Verdet constant of the system get drastically modified with a single photon. We obtained a Verdet constant of 1128.94 Rad/m-T from a single photon data compared to the value of 910.97 Rad/m-T when 10^16 photons/s are used. There is no clear hypothesis of why this discrepancy of 20% happens. We speculate in this paper that this may be the result of local effects that become relevant when a single photon is used, or if we take the notion put forward by Dirac that the polarization is an intrinsic property of the photon, then a collective effect may be relevant when 10^16 photons/s are used as compared to the case of a single photon.