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arXiv · 2109.00728

Gravitational redshift induces quantum interference

David Edward Bruschi·Andreas W. Schell
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Abstract

We use quantum field theory in curved spacetime to show that gravitational redshift induces a unitary transformation on the quantum state of propagating photons. This occurs for realistic photons characterized by a finite bandwidth, while ideal photons with sharp frequencies do not transform unitarily. We find that the transformation is a mode-mixing operation, and we devise a protocol that exploits gravity to induce a Hong-Ou-Mandel-like interference effect on the state of two photons. Testing the results of this work can provide a demonstration of quantum field theory in curved spacetime.

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David Edward Bruschi, Andreas W. Schell. 2022-12-16. Gravitational redshift induces quantum interference. https://doi.org/10.1002/andp.202200468

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