Abstract The burgeoning intersection of particle physics and quantum information science unveils significant connections, particularly in the context of neutrinos–fundamental particles that challenge our understanding of mass, mixing, and coherence at the quantum level. This work investigates the quantum informational aspects of two-flavor neutrino oscillations, treating neutrino flavor change as a dynamic carrier of quantum resources in addition to a fundamental lepton physics phenomenon. Employing realistic experimental parameters from the Daya Bay, KamLAND, and MINOS experiments, we systematically evaluate four key quantum metrics: quantum coherence, entanglement, local quantum Fisher information (LQFI), and Bell non-locality. Our formalism utilizes time-dependent density matrices, incorporating environmental interactions modeled by a correlated dephasing channel to capture both Markovian (memoryless) and non-Markovian (memory-retaining) regimes. In the Markovian regime, coherence and LQFI exhibit exponential decay, with MINOS demonstrating the highest persistence of quantum features attributed to its long baseline (735 km) and high energy range (0.5–50 GeV). KamLAND, with a medium baseline and moderate energy, shows intermediate behavior, while Daya Bay’s short baseline limits the survival of these quantum properties. Notably, Bell non-locality violation in the Markovian regime is exclusive to MINOS under high classical correlation strength, whereas Daya Bay and KamLAND remain within classical bounds. Across both regimes, particularly the non-Markovian where information backflow enhances coherence and entanglement, MINOS consistently emerges as the most robust setup for the preservation of quantum information.
Abstract The burgeoning intersection of particle physics and quantum information science unveils significant connections, particularly in the context of neutrinos–fundamental particles that challenge our understanding of mass, mixing, and coherence at the quantum level. This work investigates the quantum informational aspects of two-flavor neutrino oscillations, treating neutrino flavor change as a dynamic carrier of quantum resources in addition to a fundamental lepton physics phenomenon. Employing realistic experimental parameters from the Daya Bay, KamLAND, and MINOS experiments, we systematically evaluate four key quantum metrics: quantum coherence, entanglement, local quantum Fisher information (LQFI), and Bell non-locality. Our formalism utilizes time-dependent density matrices, incorporating environmental interactions modeled by a correlated dephasing channel to capture both Markovian (memoryless) and non-Markovian (memory-retaining) regimes. In the Markovian regime, coherence and LQFI exhibit exponential decay, with MINOS demonstrating the highest persistence of quantum features attributed to its long baseline (735 km) and high energy range (0.5–50 GeV). KamLAND, with a medium baseline and moderate energy, shows intermediate behavior, while Daya Bay’s short baseline limits the survival of these quantum properties. Notably, Bell non-locality violation in the Markovian regime is exclusive to MINOS under high classical correlation strength, whereas Daya Bay and KamLAND remain within classical bounds. Across both regimes, particularly the non-Markovian where information backflow enhances coherence and entanglement, MINOS consistently emerges as the most robust setup for the preservation of quantum information.
This study examines the dynamics of quantumness in two-flavor neutrino oscillations subjected to a dephasing channel, using representative oscillation parameters associated with the KamLAND, MINOS, and Daya Bay experiments. We analyze three complementary quantum-correlation measures -- entanglement of formation (EOF), quantum discord (QD), and local quantum uncertainty (LQU) -- within an effective two-qubit description. In the unitary case, all three measures display oscillatory behavior controlled by flavor mixing, and their amplitudes are strongly shaped by the relevant mixing angle. MINOS exhibits the largest correlations because θ23 is close to maximal, KamLAND shows intermediate values associated with the solar sector, and Daya Bay yields smaller correlations due to the relatively small value of θ13. Under dephasing, the off-diagonal coherence terms are suppressed and the three quantifiers decrease accordingly, while QD remains non-zero in regimes where entanglement is weak. For pure states, LQU satisfies U=C2 and therefore tracks entanglement monotonically, whereas QD provides a broader witness of non-classical correlations. These results provide a compact quantum-information description of two-flavor neutrino oscillations in both coherent and dephased regimes. We also quantify the sensitivity of these observables to oscillation and decoherence parameters, showing that their main added value relative to flavor probabilities is their direct response to off-diagonal coherence loss.
Neutrino oscillations confirm the presence of mode entanglement, as each flavor eigenstate is composed of a coherent superposition of distinct mass eigenstates. In this work, we investigate the dynamics of quantum resources in neutrino oscillation systems by analyzing quantum steering, logarithmic negativity, and quantum coherence within a two-flavor framework. Treating neutrino oscillations as an effective two-level quantum system, we study the influence of environmental decoherence on these nonclassical features by modeling the system as an open quantum system. Three representative noise channels are considered, namely amplitude damping (AD), phase flip (PF), and phase damping (PD), allowing us to capture both dissipative and dephasing mechanisms. We examine the evolution of quantum resources in both Markovian and non-Markovian regimes, highlighting the role of memory effects in the system-environment interaction. The results reveal a clear hierarchy in the robustness of quantum resources under decoherence. Quantum steering is the most sensitive correlation in the hierarchy under decoherence effects, while logarithmic negativity exhibits intermediate robustness. Quantum coherence displays the highest resilience by persisting over a wider parameter range. Within the PF and PD channels, both logarithmic negativity and coherence display identical dynamical behaviors, a feature that reflects their shared dependence on phase-related noise. In contrast, the non-Markovian regime delays decoherence and induces partial revivals of entanglement and coherence due to information backflow, whereas quantum steering remains strongly suppressed. These findings provide a detailed comparison of different quantum resources in neutrino oscillation systems and offer new insights into the interplay between decoherence mechanisms and quantum correlations.
Neutrino oscillations confirm the presence of mode entanglement, as each flavor eigenstate is composed of a coherent superposition of distinct mass eigenstates. In this work, we investigate the dynamics of quantum resources in neutrino oscillation systems by analyzing quantum steering, logarithmic negativity, and quantum coherence within a two-flavor framework. Treating neutrino oscillations as an effective two-level quantum system, we study the influence of environmental decoherence on these nonclassical features by modeling the system as an open quantum system. Three representative noise channels are considered, namely amplitude damping (AD), phase flip (PF), and phase damping (PD), allowing us to capture both dissipative and dephasing mechanisms. We examine the evolution of quantum resources in both Markovian and non-Markovian regimes, highlighting the role of memory effects in the system-environment interaction. The results reveal a clear hierarchy in the robustness of quantum resources under decoherence. Steering is the most sensitive correlation in the hierarchy under decoherence effects. while logarithmic negativity exhibits intermediate robustness. Quantum coherence displays the highest resilience, persisting over a wider range of parameters. In the PF and PD channels, logarithmic negativity and coherence are shown to exhibit identical dynamical behavior, reflecting their common dependence on phase-related noise. In contrast, the non-Markovian regime leads to delayed decoherence and partial revivals of entanglement and coherence due to information backflow, whereas quantum steering remains strongly suppressed. These findings provide a comparison of different quantum resources in neutrino oscillation systems and offer new insights into the interplay between decoherence mechanisms and quantum correlations.
Abstract Neutrino oscillation is an important physical phenomenon in elementary particle physics, and its nonclassical features can be revealed by the Leggett–Garg inequality. It shows that its quantum coherence can be sustained over astrophysical length scales. In this work, we investigate the measure of quantumness in experimentally observed neutrino oscillations via the nonlocal advantage of quantum coherence (NAQC), quantum steering, and Bell nonlocality. From various neutrino sources, ensembles of reactor and accelerator neutrinos are analyzed at distinct energies, such as Daya Bay (0.5 km and 1.6 km) and MINOS (735 km) collaborations. The NAQC of two-flavor neutrino oscillation is characterized experimentally compared to the theoretical prediction. It exhibits non-monotonously evolutive phenomenon with the increase of energy. Furthermore, it is found that the NAQC is a stronger quantum correlation than quantum steering and Bell nonlocality even in the order of km. Hence, for an arbitrary bipartite neutrino-flavor state with achieving a NAQC, it must be also a steerable and Bell nonlocal state. The results might offer an insight into the neutrino oscillation for the further applications on quantum information processing.
We evaluate the Hellinger-distance coherence of the two-flavor neutrino state subject to Lindblad damping of the mass-eigenstate interference term, and obtain a closed expression in terms of the flavor-basis density-matrix elements. In the two-flavor vacuum treatment with negligible wave-packet separation, the undamped state is pure, and the smallest eigenvalue of the damped state grows linearly with ε=1−κ, where κ=e−ΓL. An expansion about the pure state then yields a nonanalytic ε correction to the Hellinger coherence, with coefficient K=22usin2θ/1−2u, whereas the flavor-transition probability, the l1 coherence, the concurrence, the entanglement of formation and the local quantum Fisher information all respond linearly in ε. Using representative Daya Bay, KamLAND and MINOS working points together with a current 90% C.L. bound on energy-independent damping, we find fractional changes in the Hellinger coherence of 0.18%, 9.40% and 21.51%, against 0.0009%, 0.43% and 1.81% for the concurrence. The comparison concerns the response of the quantifiers to the damping parameter and carries no implication about experimental resolution. The same mechanism operates, with a different coefficient, for a correlated dephasing channel acting on the flavor coherence, where the non-Markovian regime produces damped revivals.
Abstract Since neutrino oscillations (NOs) show nonclassical features with the Leggett–Garg inequality and exhibit potential applications in quantum information processing and telecommunications, in order to further reveal quantum properties of the NO systems, we herein focus on investigating entanglement and entropic uncertainty relation in the context of three-flavor NOs. Specifically, we take advantage of three different types of entanglement measures to characterize quantum resources originating from NO systems, and examine the hierarchical relationship among them. Moreover, we analyze the experiment data from different neutrino sources including Daya Bay (0.5 and 1.6 km) and MINOS+ (735 km) collaborations in comparison with our theoretical results. We find that the dynamical evolution of both the entropic uncertainty and entanglement of system shows non-monotonicity, and the experimental results coincide with our theoretical prediction very well. Interestingly, it shows that neutrinos always maintain quantum properties during oscillation process. More importantly, we reveal that the variation of the uncertainty is almost anti-correlated with that of the entanglement of system. Therefore, the nature of entanglement and uncertainty in NOs can be explored in the practical experiment when the three-flavor neutrino states are treated as three-qubit ones, which might be useful for the potential NO-based applications on prospective quantum information processing.