In this paper, we explore the dynamics of nonlocal correlations in a two-qubit system, that is, first prepared in a Gisin state and then interacts with a bosonic non-Markovian environment. We employ uncertainty-induced nonlocality (UIN) and the Horodecki measure (Bell function) to characterize the degree of nonclassical correlations and quantum nonlocality in the system, taking into account the influence of the non-Markovian reservoir. The dynamics of the UIN and the Bell nonlocality are next examined using the various parameters that define the non-Markovian reservoir and the initial Gisin state. Our results show that the amount of nonlocal correlations and the degree of violation of Bell’s inequality can be modulated by varying the physical parameters characterizing the non-Markovian reservoir and the initial Gisin state. We also show that in some specific cases, the system exhibits nonclassical correlations while the evolved Gisin state does not violate Bell’s inequality. Our results also confirm that UIN is robust than Bell’s nonlocality in the presence of decoherence induced by the interaction with the non-Markovian reservoir.In this paper, we explore the dynamics of nonlocal correlations in a two-qubit system, that is, first prepared in a Gisin state and then interacts with a bosonic non-Markovian environment. We employ uncertainty-induced nonlocality (UIN) and the Horodecki measure (Bell function) to characterize the degree of nonclassical correlations and quantum nonlocality in the system, taking into account the influence of the non-Markovian reservoir. The dynamics of the UIN and the Bell nonlocality are next examined using the various parameters that define the non-Markovian reservoir and the initial Gisin state. Our results show that the amount of nonlocal correlations and the degree of violation of Bell’s inequality can be modulated by varying the physical parameters characterizing the non-Markovian reservoir and the initial Gisin state. We also show that in some specific cases, the system exhibits nonclassical correlations while the evolved Gisin state does not violate Bell’s inequality. Our results also confirm that UIN is robust than Bell’s nonlocality in the presence of decoherence induced by the interaction with the non-Markovian reservoir.

Modern Physics Letters AAug 30, 202213 citations

Hierarchy of quantum correlations in qubit-qutrit axially symmetric states

Venkat Abhignan, R. Muthuganesan

We investigate quantum correlations in a hybrid qubit-qutrit system subject to both axial and planar single-ion anisotropies, dipolar spin-spin interactions, and Dzyaloshinskii-Moriya (DM) coupling. Using Negativity, Measurement-Induced Non-locality (MIN), Uncertainty-Induced Nonlocality (UIN), and Bell nonlocality (as quantified by the CHSH inequality) as measures, we analyze the interplay between anisotropy parameters, magnetic fields, and temperature on the survival of quantum correlations. Our results demonstrate that Bell nonlocality and entanglement (Negativity) are highly sensitive to temperature and anisotropy, exhibiting sudden death under thermal noise, whereas MIN and UIN are significantly more robust. In particular, these discord-like and information-theoretic measures provide the largest baseline and persist even in parameter regions where entanglement vanishes, highlighting their suitability as a quantumness witness in realistic conditions. Notably, our Bell nonlocality study is tailored to the asymmetric qubit-qutrit setting by exploiting a recently developed qubit-qudit CHSH maximization framework. However, Bell nonlocality is confirmed to be the most fragile, surviving only in narrow parameter windows at low temperature. A key finding of this work is that we observe the fragility hierarchy: Bell nonlocality $\subseteq$ Negativity $\subseteq$ UIN(MIN) in the qubit-qutrit setting. These results provide deeper insight into the relative robustness of distinct quantum resources in anisotropic qubit-qutrit models, suggesting that quantum discord-like measures, such as MIN and UIN, may serve as more practical resources than entanglement for quantum information tasks in thermally active spin systems.We investigate quantum correlations in a hybrid qubit-qutrit system subject to both axial and planar single-ion anisotropies, dipolar spin-spin interactions, and Dzyaloshinskii-Moriya (DM) coupling. Using Negativity, Measurement-Induced Non-locality (MIN), Uncertainty-Induced Nonlocality (UIN), and Bell nonlocality (as quantified by the CHSH inequality) as measures, we analyze the interplay between anisotropy parameters, magnetic fields, and temperature on the survival of quantum correlations. Our results demonstrate that Bell nonlocality and entanglement (Negativity) are highly sensitive to temperature and anisotropy, exhibiting sudden death under thermal noise, whereas MIN and UIN are significantly more robust. In particular, these discord-like and information-theoretic measures provide the largest baseline and persist even in parameter regions where entanglement vanishes, highlighting their suitability as a quantumness witness in realistic conditions. Notably, our Bell nonlocality study is tailored to the asymmetric qubit-qutrit setting by exploiting a recently developed qubit-qudit CHSH maximization framework. However, Bell nonlocality is confirmed to be the most fragile, surviving only in narrow parameter windows at low temperature. A key finding of this work is that we observe the fragility hierarchy: Bell nonlocality $\subseteq$ Negativity $\subseteq$ UIN(MIN) in the qubit-qutrit setting. These results provide deeper insight into the relative robustness of distinct quantum resources in anisotropic qubit-qutrit models, suggesting that quantum discord-like measures, such as MIN and UIN, may serve as more practical resources than entanglement for quantum information tasks in thermally active spin systems.

quant-pharXiv:2601.12292The European Physical Journal PlusJan 20, 20261 citation

Quantum Nonlocality and Reality

Mary Bell, Shan Gao

Sep 1, 20168 citations

Nonlocality in Quantum Physics

Andrey Anatoljevich Grib, Waldyr A. Rodrigues

Springer eBooksJan 1, 199954 citations

Nonlocal correlation dynamics of two qubits interacting with a cavity coherent field: time-dependent atomic location effects

Mostafa Hashem, Fahad Aljuaydi, Atta Ur Rahman +1 more

Abstract This work delves into the nonlocal correlation dynamics of the maximum-Bell nonlocality (MBN), uncertainty-induced nonlocality (UIN), and concurrence of two two-level atoms having time-dependent atomic locations within Tavis-Cummings model. By considering a scenario where the pure two qubits resonantly interact with an even coherent cavity field through a two-photon transition, we explore the nonlocal correlation dynamics of both moving and stationary two-atom configurations under varying conditions and coupling parameters. Our findings reveal that the coherent cavity induces the successful generation of nonlocal correlations between atoms in both modes, with moving atoms exhibiting higher and symmetrical nonlocal correlations. Interestingly, dynamical maps showcase distinct behaviors for atoms at rest, exhibiting precocity at higher atom-cavity strengths. Moreover, equal coupling strength results in lower quantum correlations. The UIN measure emerges as the most robust quantum function, showing enhancements with sustained unequal coupling strengths, contrasting with the MBN and concurrence. These insights offer a nuanced understanding of nonlocal correlations in the Tavis-Cummings model, essential for advancing quantum information science and technology.Abstract This work delves into the nonlocal correlation dynamics of the maximum-Bell nonlocality (MBN), uncertainty-induced nonlocality (UIN), and concurrence of two two-level atoms having time-dependent atomic locations within Tavis-Cummings model. By considering a scenario where the pure two qubits resonantly interact with an even coherent cavity field through a two-photon transition, we explore the nonlocal correlation dynamics of both moving and stationary two-atom configurations under varying conditions and coupling parameters. Our findings reveal that the coherent cavity induces the successful generation of nonlocal correlations between atoms in both modes, with moving atoms exhibiting higher and symmetrical nonlocal correlations. Interestingly, dynamical maps showcase distinct behaviors for atoms at rest, exhibiting precocity at higher atom-cavity strengths. Moreover, equal coupling strength results in lower quantum correlations. The UIN measure emerges as the most robust quantum function, showing enhancements with sustained unequal coupling strengths, contrasting with the MBN and concurrence. These insights offer a nuanced understanding of nonlocal correlations in the Tavis-Cummings model, essential for advancing quantum information science and technology.

Laser Physics LettersMar 12, 20250 citations

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Negativity

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UIN(MIN) in the qubit-qutrit setting. These results provide deeper insight into the relative robustness of distinct quantum resources in anisotropic qubit-qutrit models, suggesting that quantum discord-like measures, such as MIN and UIN, may serve as more practical resources than entanglement for quantum information tasks in thermally active spin systems.