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arXiv · 0708.2215

Polarization rotation for light propagating non-parallel to a magnetic field in QED vacuum and in a dilute electron gas

H. Perez Rojas·E. Rodriguez Querts
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Abstract

The rotation of the polarization vector for light propagating perpendicular to an external constant external magnetic field $B$, is calculated in quantum vacuum, where it leads to different photon eigenmodes of the magnetized photon self-energy tensor for polarizations along and orthogonal to $B$ (Cotton-Mouton effect in QED vacuum). Its analogies and differences with Faraday effect are discussed and both phenomena are calculated for a relativistic electron gas at low densities, by starting from the low energy limit of the photon self-energy eigenvalues in presence of $B$. In the Cotton-Mouton case the polarization vector describes an ellipse whose axes vary periodically from zero to a maximum value. By assuming an effective electron density of order $10^3$ cm$^{-3}$ the quantum relativistic eigenvalues lead to a rotation of the polarization plane compatible with some of the limit values reported by PVLAS experiments. Other consequences, which are interesting for astrophysics, are also discussed.

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H. Perez Rojas, E. Rodriguez Querts. 2008-05-02. Polarization rotation for light propagating non-parallel to a magnetic field in QED vacuum and in a dilute electron gas. https://arxiv.org/abs/0708.2215

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