Abstract This research investigates the dynamics of entanglement and uncertainty‐induced nonlocality (UIN) in a spin‐1/2 Ising‐Heisenberg diamond chain subjected to local non‐Markovian decoherence channels. By examining amplitude damping (AD) and random telegraph noise (RTN) in both zero and finite temperature regimes, the study reveals nuanced distinctions in the degradation and revival of quantum correlations. The interplay between intrinsic spin couplings, thermal effects, and memory‐induced coherence backflow highlights the complex behavior of quantum resources under realistic noise conditions. Concurrence emerges as a sensitive marker of entanglement recovery in dephasing environments, while uncertainty‐induced nonlocality proves more resilient in high‐temperature or dissipative regimes. The analysis further demonstrates that moderate thermal activation and external magnetic fields can nontrivially enhance or suppress quantum features depending on system parameters. These findings offer a detailed perspective on the robustness and complementarity of different quantum correlation measures, providing guiding principles for the design of thermally stable and noise‐resilient quantum information protocols.
Abstract This research investigates the dynamics of entanglement and uncertainty‐induced nonlocality (UIN) in a spin‐1/2 Ising‐Heisenberg diamond chain subjected to local non‐Markovian decoherence channels. By examining amplitude damping (AD) and random telegraph noise (RTN) in both zero and finite temperature regimes, the study reveals nuanced distinctions in the degradation and revival of quantum correlations. The interplay between intrinsic spin couplings, thermal effects, and memory‐induced coherence backflow highlights the complex behavior of quantum resources under realistic noise conditions. Concurrence emerges as a sensitive marker of entanglement recovery in dephasing environments, while uncertainty‐induced nonlocality proves more resilient in high‐temperature or dissipative regimes. The analysis further demonstrates that moderate thermal activation and external magnetic fields can nontrivially enhance or suppress quantum features depending on system parameters. These findings offer a detailed perspective on the robustness and complementarity of different quantum correlation measures, providing guiding principles for the design of thermally stable and noise‐resilient quantum information protocols.
Abstract This work investigates the dynamics of quantum correlations and entanglement in a thermal bipartite dipolar spin system with Dzyaloshinskii–Moriya (DM) interaction, subjected to both Markovian and non-Markovian noise. By analyzing amplitude damping and random telegraph noise channels, we derive explicit analytic forms for the thermal density matrix and quantify coherence, concurrence, quantum discord, local quantum uncertainty (ℒ𝓠𝒰), and teleportation fidelity. Our results reveal that the interplay of temperature and DM interaction crucially governs the robustness of quantum resources. In particular, non-Markovian regimes exhibit memory-induced oscillatory revivals, while Markovian channels produce irreversible decay. Importantly, we identify a hierarchy of robustness, with coherence being more resilient than discord, which in turn surpasses entanglement and ℒ𝓠𝒰, providing design principles for preserving quantum correlations. These findings extend existing open-system studies by highlighting the role of DM interaction and dipolar coupling in tailoring noise resilience, offering practical implications for solid-state spintronics and quantum communication.
The engineering features of transmitting mediums and their impact on different characteristics of a quantum system play a significant role in the efficient performance of nonlocal protocols. For this purpose, the dynamics of open quantum systems and coupling mediums remain a pathway. In this work, we investigate the dynamics of quantum correlations using negativity, uncertainty-induced nonlocality, and local quantum Fisher information in a hybrid qubit-qutrit thermal state when coupled with a magnetic field and influenced by random telegraph noise. Different features of the system parameters are taken into account while designing longer preservation of qubit-qutrit correlations. We show that the temperature has an inverse impact on the initial values of negativity, uncertainty-induced nonlocality, and local quantum Fisher information. When the magnetic field is characterized by different features, the entanglement, nonlocality, and Fisher information show a variety of dynamical maps, assuring their distinct nature. In addition, the qubit-qutrit correlations undergo repeated revivals when the configuration is restricted to the non-Markovian regime. On the other hand, an exponential drop with a single minimum is observed in the Markovian regime of the coupled field. Most importantly, our findings reveal that the present coupled fields have several advantages that can be leveraged to generate the optimal degree of entanglement, nonlocality, and local quantum Fisher information preservation in quantum dynamical maps.
Abstract Non-Markovian dynamics is central to quantum information processing, as memory effects strongly influence coherence preservation, metrology, and communication. In this work, we investigate the role of stochastic system–bath couplings in shaping non-Markovian behavior of open quantum systems, using the central spin model within a time-convolutionless master equation framework. We show that the character of the reduced dynamics depends jointly on the intrinsic memory of the environment and on the structure of the system–environment interaction. In certain regimes, the dynamics simplify to pure dephasing, while in general both amplitude damping and dephasing contribute to the evolution. By employing two complementary measures: the Quantum Fisher Information (QFI) flow and the Breuer–Laine–Piilo (BLP) measure, we demonstrate that QFI flow may fail to witness memory effects in weak-coupling and near-resonant regimes, whereas the BLP measure still detects information backflow. Furthermore, external modulation of the interaction kernel produces qualitatively richer behavior, including irregular and frequency-dependent revivals of non-Markovianity. These results clarify the physical origin of memory effects, highlight the limitations of single-witness approaches, and suggest that stochasticity and modulation can be harnessed to engineer robust, noise-resilient quantum technologies.
ABSTRACT Quantum entanglement enables advanced quantum technologies, including secure communication and quantum computing. This study investigates the temporal dynamics of GHZ‐type entangled states in a three‐photon system subjected to pure environmental dephasing noise. We distinguish between Markovian regimes, characterized by memoryless decay, and non‐Markovian regimes, where environmental memory effects induce information backflow and can generate revivals of non‐separable quantum correlations. Employing genuine multipartite concurrence to quantify genuine tripartite entanglement and quantum mutual information to evaluate total correlations, we analyze the evolution of these quantum resources under symmetric and asymmetric photon‐environment couplings. Key tunable parameters – including the relative weighting of the two peaks in the double‐Gaussian environmental frequency profile, refractive index difference, spectral width, and overall frequency distribution – are explored within experimentally realistic ranges achievable with photonic platforms such as Fabry–Pérot cavities. Our results provide that non‐Markovian environments substantially enhance the robustness of entanglement, exhibiting prominent oscillatory revivals under symmetric peak weightings, whereas more asymmetric configurations result in faster monotonic decay. These findings propose practical strategies, such as optimized cavity configurations, to suppress decoherence and prolong the lifetime of multipartite quantum correlations, thereby supporting the development of more resilient photonic quantum states for quantum technologies.
Quantum correlations and coherence in a two-qubit anisotropic XY under magnetic field
We study thermal quantum correlations and coherence in Heisenberg XY model with anisotropic interactions under a uniform magnetic field $ B $. Using concurrence C, local quantum uncertainty (LQU), Bell-Clauser-Horne-Shimony-Holt (CHSH) nonlocality $ \mathbb{B}$, and coherence Cl as quantifiers, we analyze how magnetic anisotropy $ δ_m $, coupling anisotropy $ δ_c $, Dzyaloshinskii-Moriya (DM) interaction $ D $, temperature $ T $, and magnetic field $ B $ modulate quantum resources. At low temperatures and relevant magnetic fields, the entanglement is maximized, but exhibits sudden death for $ δ_m = 0 $, which turns into a smooth decay as $ δ_m $ increases, highlighting its stabilizing role. LQU shows that stronger anisotropy suppresses quantum correlations, while $ \mathbb{B} $ induces a non-monotonic response peaking at a critical field $ B_c .Bell−CHSHnonlocalityviolations( \mathbb{B} > 2 $) persist below $ B_c ,butthermalnoise( T \geq 1 $) suppresses them. Coherence $ C_l $ is most robust to thermal fluctuations, especially for high δm, which also dampens abrupt quantum phase transitions. The DM interaction is essential for entanglement generation, with $ D $ and anisotropy synergistically enhancing correlation resilience. We identify a hierarchy of thermal degradation: nonlocality ($ \mathbb{B} )vanishesfirst,followedbyentanglement( C $), then general quantum correlations (LQU), while coherence $ C_l $ persists the longest. These results demonstrate tunable control of quantum resources via anisotropy and external parameters, providing insights for the design of robust spin-based quantum technologies.
Abstract The thermal behavior of quantum correlations is explored in a two‐qubit system based on nitrogen‐vacancy (NV) centers, using Local Quantum Fisher Information (LQFI), Local Quantum Uncertainty (LQU), and concurrence as quantifiers. These results show that entanglement, measured byconcurrence (CE), decays rapidly with increasing temperature, whereas coherence‐based measures such as LQFI and LQU display greater resilience. The strength of zero‐field splitting plays a key role in shaping quantum correlations, significantly suppressing entanglement at higher values while helping to preserve coherence. External magnetic and electric fields further influence these dynamics–magnetic fields tend to suppress entanglement, while electric fields accelerate its degradation. Dipole–dipole interactions enhance the initial quantum correlations but have a limited effect on their thermal decay. Overall, these findings underscore the robustness of coherence‐based quantum resources and suggest that, while dipole–dipole coupling is more effective at regulating quantum correlations, optimal tuning of system parameters can significantly improve both the generation and preservation of these correlations at finite temperatures.