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arXiv · 2106.13426

Polarization rotation and near-Earth quantum communications

Pravin Kumar Dahal·Daniel R. Terno
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Abstract

We revisit polarization rotation due to gravity, known as the gravitational Faraday effect, with a view on its role in quantum communications with Earth-orbiting satellites. In a static spherically symmetric gravitational field Faraday rotation is purely a reference frame (gauge) effect. This is so also in the leading post-Newtonian expansion of the Earth's gravitational field. However, establishing the local reference frame with respect to distant stars leads to the nonzero Faraday phase. In communications between a ground station and an Earth-orbiting spacecraft this phase is of the order of 10^-10. Under the same conditions the Wigner phase of special relativity is typically of the order 10^-4--10^-5. These phases lead to the physical lower bound on communication errors. However, both types of errors can be simultaneously mitigated. Moreover, they are countered by a fully reference frame independent scheme that also handles arbitrary misalignment between the reference frames of sender and receiver.

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Pravin Kumar Dahal, Daniel R. Terno. 2021-06-25. Polarization rotation and near-Earth quantum communications. https://doi.org/10.1103/physreva.104.042610

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