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arXiv:2512.10091

Entanglement in the Schwinger effect

Dimitrios Kranas, Amaury Marchon, Silvia Pla

hep-thgr-qcquant-phSubmitted Dec 10, 2025• Announced Dec 12, 2025• Revised Feb 12, 2026 (v2)
v1 · Dec 10, 2025v2 · Feb 12, 2026
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Abstract

We analyze entanglement generated by the Schwinger effect using a mode-by-mode formalism for scalar and spinor QED in constant backgrounds. Starting from thermal initial states, we derive compact, closed-form results for bipartite entanglement between particle-antiparticle partners in terms of the Bogoliubov coefficients. For bosons, thermal fluctuations enhance production but suppress quantum correlations: the logarithmic negativity is nonzero only below a (mode-dependent) critical temperature $T_c$. At fixed $T$, entanglement appears only above a critical field $E_{\text{entang}}$. For fermions, we observe a qualitatively different pattern: the fermionic logarithmic negativity is non-vanishing at finite temperature, and is monotonically suppressed by thermal noise. As a function of the electric field, it is non-monotonic, featuring a temperature-independent optimal field strength $E_*$ and decreasing on both sides of the maximum. We give quantitative estimates for analog experiments, where our entanglement criteria convert directly into concrete temperature and electric field constraints. These findings identify realistic regimes where the quantum character of Schwinger physics may be tested in the laboratory.

Comments
In v2: fermionic section updated to include the fermionic logarithmic negativity; conclusions and related figures changed accordingly. New references added. 35 pages and 7 figures;

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