We investigate neutrino flavor oscillations in the wave packet formalism, extending the standard planewave treatment to incorporate the finite spatial coherence of neutrino mass eigenstates.We derive the full three flavor oscillation probability with MSW matter effects, decoherence, and localization suppression governed by the wave packet width, benchmarking against MINOS disappearance data and extending to DUNE predictions under the same parameters. To quantify how sharply the oscillation data constrain the wave packet width, we compute the classical Fisher information FC as a function of neutrino energy for both MINOS and DUNE, and show that its sensitivity is concentrated precisely in the low-energy regime where the wave-packet and plane-wave predictions diverge. Beyond the oscillation probability analysis, we compute wave particle entanglement complementarity quantities within a quantum information theoretic framework and explore the complete triality description involving entanglement, predictability, and visibility as functions of neutrino energy for both experiments such as MINOS and DUNE. We show that even when the oscillation probability is numerically indistinguishable from the planewave result, the wave packet structure leaves observable imprints in these triality measures. Our results demonstrate that the wave packet approach provides a theoretically consistent and experimentally motivated framework for probing quantum foundations in long-baseline atmospheric neutrino oscillation experiments.
We investigate wave–particle–entanglement complementarity in three-flavor neutrino oscillations within a quantum information–theoretic framework. By considering three-flavor oscillation along with the possible entanglement between the detector and the propagation states, we extend beyond the usual wave-particle duality and arrive at a more complete triality description involving predictability, visibility, and entanglement. Using reduced density matrices and considering I-concurrence as an entanglement measure, we show that the total information carried by the system is conserved and naturally organized through the relation P 2 + V 2 + E 2 = 1 . While predictability and visibility exhibit the expected complementary behavior, we show that entanglement encodes additional wave-like information that is not captured by visibility alone. We apply our formalism to realistic long-baseline neutrino experiments, namely DUNE and T2K , and find that at the first oscillation maximum, a simultaneous characterization of the particle-like and wave-like nature of neutrinos becomes possible through the combined measurement of predictability and entanglement. Our results provide a unified operational interpretation of neutrino oscillations and highlight the role of quantum correlations in extending wave–particle duality to multipartite systems.
We investigate wave--particle--entanglement complementarity in three-flavor neutrino oscillations within a quantum information--theoretic framework. Treating neutrino flavor evolution as an open quantum system and explicitly accounting for detector--propagation correlations, we extend the conventional wave--particle duality relation to a triality relation involving predictability, visibility, and entanglement. Using reduced density matrices and I-concurrence as a quantitative measure of entanglement, we demonstrate that the total information content of the system satisfies the relation
P2+V2+E2=1. While predictability and visibility exhibit the expected complementary behavior, we show that entanglement encodes additional wave-like information that is not captured by visibility alone. We apply our formalism to realistic long-baseline neutrino experiments, namely \textsf{DUNE} and \textsf{T2K}, and find that at the first oscillation maximum, a simultaneous characterization of the particle-like and wave-like nature of neutrinos becomes possible through the combined measurement of predictability and entanglement. Our results provide a unified operational interpretation of neutrino oscillations and highlight the role of quantum correlations in extending wave--particle duality to multipartite systems.
The flavor oscillations in the neutrino system are known to be related to the multimode entanglement of a single particle state. Neutrino oscillations are shown to encompass not only quantum superposition among different mass eigenstates but also a single-particle multimode entanglement in the flavor basis as they propagate. In the framework of three flavor neutrino oscillations, we demonstrate that the measures of entanglement can be expressed in terms of experimentally accessible appearance and disappearance probabilities. We explicitly show here that the genuine tripartite entanglement measure, i.e., the tangle, vanishes identically for all flavors, signifying that a three flavor neutrino system forms a W-type entangled state. Further, we investigate alternative measures of tripartite entanglement like the partial tangle and the concurrence fill, which capture the total sharing of entanglement beyond pairwise correlations. In terms of bipartite and bipartitioned entanglement measures, we derive the symmetric invariant and the concurrence fill, which quantify the distributed entanglement and are completely expressible in terms of flavor transition probabilities. These entanglement measures display distinct energy dependent patterns across the oscillation window, which can be experimentally accessible in the long baseline experiments like DUNE, providing an alternative quantum information perspective on flavor evolution. We use General Long Baseline Experiment Simulator simulations within the DUNE setup to investigate these tripartite entanglement measures in terms of neutrino energy and the length of the baseline. It is observed that, at the point of maximal mixing, these measures show near maximal entanglement between the muon and the tau flavor modes, establishing entanglement monogamy. Within the DUNE setup, the wide band of energy and expected higher sensitivity to C P violation at the second oscillation maximum provide a unique advantage to explore the quantum correlation effects across a broader energy window. Thus, the flavor coherence and C P -phase dependent interference can influence the quantum entanglement measures among neutrino flavor modes, and thereby, such potential new physics effects can be probed in current or future planned neutrino experiments.
Abstract Quantum correlations provide a fertile testing ground for investigating fundamental aspects of quantum physics in various systems, especially in the case of relativistic (elementary) particle systems as neutrinos. In a recent paper, Ming et al. (Eur Phys J C 80:275, 2020), in connection with results of Daya-Bay and MINOS experiments, have studied the quantumness in neutrino oscillations in the framework of plane-wave approximation. We extend their treatment by adopting the wave packet approach that accounts for effects due to localization and decoherence. This leads to a better agreement with experimental results, in particular for the case of MINOS experiment.
Determination of the leptonic CP-violating phase
δCP, the atmospheric mixing angle
θ23, and the mass-squared difference
Δm312 constitutes a primary objective of current and next-generation long-baseline neutrino experiments. We employ Quantum Fisher Information (QFI) to quantify the maximum information that the neutrino quantum state contains about these oscillation parameters, treating the neutrino as an evolving pure quantum state. Computing the QFI as a function of the baseline-to-energy ratio
L/E for benchmark parameter sets from NuFit-6.0, we find distinct sensitivity hierarchies and
L/E-dependent structures. Specifically,
δCP and
θ23 exhibit bimodal QFI profiles with peaks around
L/E∼500 and
1500 km/GeV, reaching
FQ(δCP)∼0.15 and
FQ(θ23)∼15, respectively. In contrast,
FQ(Δm312) increases rapidly with
L/E over the range considered, reaching values of order
107. This hierarchy indicates that, within the considered single-parameter framework, the neutrino state carries substantially greater intrinsic quantum sensitivity to
Δm312 than to
θ23 or
δCP. We further compare the QFI with the classical Fisher information (CFI) obtained from flavor-transition probabilities, showing how much of the available information can be extracted through this specific measurement. For a fixed DUNE baseline, matter effects substantially enhance the QFI for
δCP in the few-GeV region, while producing only minor modifications for
θ23 and
Δm312. These results show that the information available for estimating the three oscillation parameters differs significantly, and that the flavor-probability measurement does not always extract all the information available in the quantum state.
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.