We investigate quantum correlations in the context of neutrino oscillations, with specific reference to Daya-Bay and MINOS experiments. We compute the non-local advantage of quantum coherence -- a valuable quantum resource -- for the two experiments, within the wave-packet approach. We find that this kind of non-local correlation may persist at long distances, when oscillations are washed out, depending on the value of the mixing angle.
We investigate quantum correlations in the context of neutrino oscillations, with specific reference to Daya-Bay and MINOS experiments. We compute the non-local advantage of quantum coherence -- a valuable quantum resource -- for the two experiments, within the wave-packet approach. We find that this kind of non-local correlation may persist at long distances, when oscillations are washed out, depending on the value of the mixing angle.
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.
Abstract We analyze quantum correlations and quantum coherence in neutrino oscillations. To this end, we exploit complete complementarity relations (CCR) that fully characterize the interplay between different correlations encoded in a quantum system both for pure and mixed states. We consider the CCR for neutrino oscillations both in the case of plane-waves (pure state) and of wave packets (mixed state). In this last case we find a complex structure of correlations depending on the mixing angle, and we show the connection with the non local advantage of quantum coherence, a relevant quantifier of coherence.
Neutrino oscillation represents an intriguing physical phenomenon where the quantumness can be maintained and detected over a long distance. Previously, the nonclassical character of neutrino oscillation was tested with the Leggett-Garg inequality, where a clear violation of the classical bound was observed [J. A. Formaggio et al., Phys. Rev. Lett. 117, 050402 (2016)]. However, there are several limitations in testing neutrino oscillations with the Leggett-Garg inequality. In particular, the degree of violation of the Leggett-Garg inequality cannot be taken as a ``measure of quantumness.'' Here, we focus on quantifying the quantumness of experimentally observed neutrino oscillation, using the tools of the recently developed quantum resource theory. We analyzed ensembles of reactor and accelerator neutrinos at distinct energies from a variety of neutrino sources, including Daya Bay (0.5 and 1.6 km), KamLAND (180 km), MINOS (735 km), and T2K (295 km). The quantumness of the three-flavored neutrino oscillation is characterized within a $3\ensuremath{\sigma}$ range relative to the theoretical prediction. It is found that the maximal coherence was observed in the neutrino source from the KamLAND reactor. However, even though the survival probability of the Daya Bay experiment did not vary significantly (it dropped about 10%), the coherence recorded can reach up to 40% of the maximal value. These results represent the longest distance over which quantumness was experimentally determined for quantum particles other than photons.
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.
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.
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.