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arXiv:2607.20264 · Physics Letters B

Dynamical redistribution of quantum resources in tree-level Bhabha scattering

Zan Cao, Meng-Long Song, Xue-Ke Song, Liu Ye, Dong Wang

quant-phSubmitted Jul 22, 2026• Announced Jul 23, 2026• 0 citations• Revised Aug 19, 2026 (v2)
v1 · Jul 22, 2026v2 · Aug 19, 2026
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Abstract

The fundamental interactions governed by quantum electrodynamics (QED) are intrinsically rich in quantum resources, yet how these resources dynamically redistribute during relativistic scattering is still not fully understood. In this work, we systematically investigate the tree-level Bhabha scattering process (e^- e^+ \rightarrow e^- e^+) within the framework of quantum resource theory, revealing how QED kinematics and Feynman amplitudes strictly dictate resource redistribution. Specifically, we demonstrate a strict anti-correlation between entropic uncertainty and dynamically generated entanglement across diverse initial states. We find that mass-induced single-helicity-flip transitions cause a pronounced geometric symmetry breaking in the non-relativistic regime, whereas the restoration of chiral symmetry in the ultra-relativistic limit ensures strict symmetry about the backward scattering angle. Furthermore, we analytically establish a rigorous equivalence between local wave-particle duality and global bipartite quantum coherence. Finally, evaluating the trade-off between local duality and Bell nonlocality, we show that in the ultra-relativistic limit, transverse scattering of basic factorized states equalizes the s- and t-channel amplitudes to optimize non-local correlations. However, pre-existing local coherence inevitably disrupts this delicate kinematic balance, significantly suppressing the Bell parameter and preventing the maximal violation of local realism. Therefore, we believe the present results provide deeper understanding of the fundamental quantum nature of QED processes.

Journal reference
Physics Letters B 880, 140785 (2026)
DOI
10.1016/j.physletb.2026.140785
Comments
8 pages, 5 figures, Accepted by Physics Letters B. Comments on my paper are welcome

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The fundamental interactions governed by quantum electrodynamics (QED) are intrinsically rich in quantum resources, yet how these resources dynamically redistribute during relativistic scattering is still not fully understood. In this work, we systematically investigate the tree-level Bhabha scattering process (e^- e^+ \rightarrow e^- e^+) within the framework of quantum resource theory, revealing how QED kinematics and Feynman amplitudes strictly dictate resource redistribution. Specifically, we demonstrate a strict anti-correlation between entropic uncertainty and dynamically generated entanglement across diverse initial states. We find that mass-induced single-helicity-flip transitions cause a pronounced geometric symmetry breaking in the non-relativistic regime, whereas the restoration of chiral symmetry in the ultra-relativistic limit ensures strict symmetry about the backward scattering angle. Furthermore, we analytically establish a rigorous equivalence between local wave-particle duality and global bipartite quantum coherence. Finally, evaluating the trade-off between local duality and Bell nonlocality, we show that in the ultra-relativistic limit, transverse scattering of basic factorized states equalizes the s- and t-channel amplitudes to optimize non-local correlations. However, pre-existing local coherence inevitably disrupts this delicate kinematic balance, significantly suppressing the Bell parameter and preventing the maximal violation of local realism. Therefore, we believe the present results provide deeper understanding of the fundamental quantum nature of QED processes.
From the perspective of quantum information science, we investigate tree-level Bhabha scattering between an incident electron AAA and a positron BBB, where BBB is initially entangled with a spectator electron CCC, which does not participate in the scattering interaction. We find that the quantum electrodynamics (QED) scattering between AAA and BBB can drive the global ABCABCABC system into a genuine tripartite entangled (GTE) state. Using four canonical tripartite entanglement metrics, we systematically characterize and quantify the GTE of the composite system, and demonstrate that the scattering momentum of the AAA-BBB pair and the initial BBB-CCC entanglement are the key resources governing GTE generation. We further analyze the monogamy of quantum correlations, which imposes fundamental constraints on the shareability of quantum resources in multipartite systems. Specifically, we systematically study the monogamy relations for the squared entanglement of formation and squared quantum discord in our scattering model, and find that monogamy constraints are markedly relaxed in the non-relativistic regime, enabling enhanced shareability of quantum correlations across the three particles. This work uncovers novel quantum correlation properties of fundamental QED scattering processes, and provides direct theoretical guidance for the development of QED-based quantum information processing protocols.
We exploit the complete complementarity relations (CCR) to fully characterize various aspects of quantumness in quantum electrodynamics (QED) scattering processes at tree level. As a paradigmatic example, we consider Bhabha scattering in two different configurations: in the first case, the initial state is factorized in the spin and we study the generation of entanglement due to the scattering. Then we consider the most general case in which the initial state can be entangled: we find that the scattering generates and distributes quantum information in a nontrivial way among the spin degrees of freedom of the particles, with CCR relations being preserved. An important outcome of our analysis is that maximal entanglement is conserved in the scattering process involving only fermions as input and output states, with a more complex situation if photons are present.
We analyze how entanglement is generated and distributed in a Bhabha scattering process (e−e+→e−e+)(e^-e^+\rightarrow e^-e^+)(e−e+→e−e+) at tree level. In our setup an electron AAA scatters with a positron BBB, which is initially entangled with another electron CCC (spectator), that does not participate directly to the process. We find that the QED scattering generates and distributes entanglement in a non-trivial way among the three particles: the correlations in the output channels ABABAB, ACACAC and BCBCBC are studied in detail as functions of the scattering parameters and of the initial entanglement weight. Although derived in a specific case, our results exhibit some general features of other similar QED scattering processes, for which the extension of the present analysis is straightforward.
Quantum magic, or nonstabilizerness, is a quantum resource associated with computational advantage in quantum systems. In high energy collisions, Quantum Electrodynamics (QED) is inefficient at generating magic while the weak mixing angle, a fundamental constant of nature, sits near a value that minimizes magic production in charged-lepton scattering. These observations were made in the laboratory (lab) basis, in which spin is projected along the incoming beam axis. An alternative choice is the helicity basis, in which spin is projected along the direction of motion of each particle. The transformation between these two bases is, in general, not a Clifford operation and therefore can change the amount of magic. We present a detailed study of magic production in both bases for QED and electroweak processes, and compare these results with the basis-invariant non-local magic. In the ultra-relativistic limit, magic production is generally smaller in the helicity basis due to helicity selection rules, while the lab basis generally yields less magic in the non-relativistic regime. We provide circuit realizations of the ultra-relativistic Bhabha amplitudes using linear combinations of unitaries and show that the lab basis construction contains a larger TTT-gate count at generic scattering angles. Interestingly, in both bases the physical weak mixing angle lies close to the value that minimizes magic production.
We analyze how entanglement is generated and distributed in a Bhabha scattering process $({e}^{\ensuremath{-}}{e}^{+}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}{e}^{+})$ at tree level. In our setup an electron AAA scatters with a positron BBB, which is initially entangled with another electron CCC (spectator), that does not participate directly to the process. We find that the QED scattering generates and distributes entanglement in a nontrivial way among the three particles; the correlations in the output channels ABABAB, ACACAC, and BCBCBC are studied in detail as functions of the scattering parameters and of the initial entanglement weight. Although derived in a specific case, our results exhibit some general features of other similar QED scattering processes, for which the extension of the present analysis is straightforward.
We investigate spin-outcome correlations and memory-assisted entropic uncertainty in tree-level Bhabha scattering, where an incident electron AAA scatters with a positron BBB initially entangled with a spectator electron CCC. For the fixed-angle post-selected final state, we compare the total memory-assisted uncertainty UAU_AUA​ for three alternative Pauli measurements on AAA with the entanglement entropy S(ρA)S(ρ_A)S(ρA​) across the A∣BCA|BCA∣BC partition. We resolve UAU_AUA​ into the separate uncertainties UBU_BUB​ and UCU_CUC​ and evaluate the corresponding outcome-memory mutual-information sums GBG_BGB​ and GCG_CGC​. This separates changes in the randomness of the outcomes on AAA from changes in their correlations with each memory. In the parameter regions studied, enhanced A∣BCA|BCA∣BC entanglement is accompanied by lower UAU_AUA​, most prominently near high-energy backscattering. An analytic treatment of this limit shows that BBB factorizes from ACACAC: GBG_BGB​ vanishes, whereas GCG_CGC​ increases with the initial BBB-CCC entanglement. An entropic complete complementarity analysis characterizes the accompanying loss of local helicity predictability in ρAρ_AρA​ and changes in the coherence, predictability, and mixedness of the interacting pair ρABρ_{AB}ρAB​. These results show that initial BBB-CCC entanglement can lower the total memory-assisted uncertainty in high-energy backscattering by strengthening spin-outcome correlations with the spectator CCC, thereby identifying the distinct roles of the interacting particle and the spectator as quantum memories.