Classical versus non-classical photon states for detecting vacuum non-linearity

• URL: http://arxiv.org/abs/2608.21361v1
• Date: Fri, 21 Aug 2026 17:59:54 GMT
• Title: Classical versus non-classical photon states for detecting vacuum non-linearity
• Abstract summary: Quantum electrodynamics (QED) predicts that the vacuum should behave as a non-linear medium.<n>Here we consider modifying these schemes by sending in a classical or non-classical (e.g., squeezed) photon state instead of the initial vacuum state in that mode.<n>We find that the detectability can be improved significantly.
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• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Quantum electrodynamics (QED) predicts that the vacuum should behave as a non-linear medium. For many schemes aimed at verifying this fundamental prediction, the signal consists of one or more photons in a certain mode (determined by polarization $σ$ and wave-number $\boldsymbol{k}$) which would be empty in the absence of a QED vacuum non-linearity. Here we consider modifying these schemes by sending in a classical or non-classical (e.g., squeezed) photon state instead of the initial vacuum state in that mode. We find that the detectability can be improved significantly.

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