Eur. Phys. J. D (2026) 80: 47
https://doi.org/10.1140/epjd/s10053-026-01140-z

Research - Photon

Phase-coherent enhancement and symmetry breaking in multi-pulse Schwinger pair production

Department of Forensic Science and Technology, Xinjiang Police College, 830011, Urumqi, China

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Received: 26 November 2025
Accepted: 28 February 2026
Published online: 3 May 2026

Abstract

We present a theoretical investigation of electron–positron pair production enhancement through quantum interference in multi-pulse electric fields combining the dynamically assisted Schwinger mechanism with time-domain multiple-slit interference. Using cosine-type subcycle pulse structures within a spatially homogeneous field model, we identify three distinct theoretical mechanisms that extend beyond previous studies employing sech$_{}^2$ pulses. First, phase-coherent pulse optimization yields higher-visibility interference patterns ($\mathrm{\Delta }{p}_{\Vert }\approx 0.027m$) compared to Li et al. (Phys Rev D 8:093011, 2014) ($\mathrm{\Delta }{p}_{\Vert }\approx 0.05m$), demonstrating enhanced temporal coherence control. Second, we observe a previously unreported momentum asymmetry ($\alpha \sim 12\%$–$15.3\%$) arising from complex-plane conjugation symmetry breaking, revealing non-Markovian memory effects absent in symmetric pulse trains. Third, Floquet-engineered spectroscopy based on quantized resonance conditions $\sqrt{{(p_{\Vert }-eA)}^2+p_{\perp }^2}=n{\omega }_2$ achieves field frequency resolution $\delta {\omega }_2\sim 0.01m$—a tenfold improvement over transverse-momentum-based analysis. Crucially, we demonstrate that local Pauli blocking in momentum space, rather than global phase-space filling, leads to $N^{1.5}$–$N^{1.6}$ scaling of production rates, deviating from the ideal $N^2$ behavior and establishing $N=5$ as the optimal pulse number due to quantum statistical constraints. These findings provide new insights into the interplay between temporal coherence, symmetry breaking, and quantum statistics in non-perturbative QED, while explicitly acknowledging the theoretical idealization of spatial homogeneity for isolating pure interference effects. The results establish fundamental limits on interference-based enhancement strategies and contribute to the foundational understanding of vacuum structure under strong electromagnetic fields.