Abstract This research explores the progression of fractional time dynamics of quantum entanglement, nonclassical correlations, and quantum coherence C l 1 in a qubit-qutrit XXZ system through an in-depth analysis of the effects of the fractional parameter τ , the exchange interaction J , the XXZ exchange anisotropy δ , and the Dzyaloshinskii-Moriya interaction (DMI) D z , and the initial state. The results reveal that lower values of τ lead to a rapid and stable increase in quantum correlations (measured by logarithmic negativity, LN, and local quantum uncertainty (LQU) but cause a faster decay in coherence C l 1 , indicating a quick loss of quantum superposition. Conversely, higher values of τ slow the dynamics of correlations, allowing coherence to persist longer. The exchange strength J similarly influences stability: low J values promote fast correlation formation but reduce coherence stability, while high J values stabilize coherence at the expense of slower correlation growth. As for the XXZ anisotropy δ and DMI strength D z , lower values promote rapid quantum correlation development but compromise coherence. In contrast, higher values help sustain C l 1 over time, limiting the intensity of correlations. The initial state is also critical: an initially partially entangled state is more resilient to perturbations. It preserves correlations over time compared to a separable state, which exhibits cycles of entanglement creation and destruction. Thus, by tuning system parameters, it is possible to control the stability and duration of correlations and coherence, providing a framework for optimizing quantum systems in applications that require both strong entanglement and durable coherence, such as quantum computing and secure communication.
Abstract This research explores the progression of fractional time dynamics of quantum entanglement, nonclassical correlations, and quantum coherence C l 1 in a qubit-qutrit XXZ system through an in-depth analysis of the effects of the fractional parameter τ , the exchange interaction J , the XXZ exchange anisotropy δ , and the Dzyaloshinskii-Moriya interaction (DMI) D z , and the initial state. The results reveal that lower values of τ lead to a rapid and stable increase in quantum correlations (measured by logarithmic negativity, LN, and local quantum uncertainty (LQU) but cause a faster decay in coherence C l 1 , indicating a quick loss of quantum superposition. Conversely, higher values of τ slow the dynamics of correlations, allowing coherence to persist longer. The exchange strength J similarly influences stability: low J values promote fast correlation formation but reduce coherence stability, while high J values stabilize coherence at the expense of slower correlation growth. As for the XXZ anisotropy δ and DMI strength D z , lower values promote rapid quantum correlation development but compromise coherence. In contrast, higher values help sustain C l 1 over time, limiting the intensity of correlations. The initial state is also critical: an initially partially entangled state is more resilient to perturbations. It preserves correlations over time compared to a separable state, which exhibits cycles of entanglement creation and destruction. Thus, by tuning system parameters, it is possible to control the stability and duration of correlations and coherence, providing a framework for optimizing quantum systems in applications that require both strong entanglement and durable coherence, such as quantum computing and secure communication.
Abstract Our work explores the time evolution of entanglement, local quantum uncertainty, and correlated coherence within a system modeled by two coupled double quantum dots. The dynamics is described using a time-fractional Schrödinger equation, which is treated here as a phenomenological effective framework introducing temporal nonlocality and memory-like effects, rather than as a first-principles open-system reduction. We vary the fractional parameter τ , the tunneling amplitudes δ A and δ B , and the inter-dot Coulomb interaction strength V , in order to investigate how these key parameters govern the generation, stabilization, and decay of quantum resources within the system. The obtained results reveal that, for both initial states (separable and partially entangled), fractional dynamics with a small τ rapidly generates entanglement reaching maximal values LN ≈ 1 together with strong non-classical correlations quantified by the local quantum uncertainty. Conversely, when τ is closer to unity, entanglement builds up more slowly but the memory-like effects allow quantum resources to remain significant for a longer time, with the negativity remaining above ≈ 0.6 . We also find that higher Coulomb-interaction frequencies V accelerate the build-up of correlations and stabilize coherence, while a strong tunneling asymmetry degrades entanglement and coherence despite the initial benefits of increasing quantum resources. We find that the standard unitary Schrödinger evolution is recovered analytically at τ = 1 , where the Mittag–Leffler functions reduce to ordinary exponentials, while decreasing τ progressively introduces fractional-time nonlocal (memory-like) effects.
Our work explore the time evolution of entanglement, local quantum uncertainty, and correlated coherence, within a system modeled by two double quantum dots. The dynamics is represented using a time-fractional Schrödinger equation, which includes memory effects in a non-Markovian regime. We vary the fractional parameter τ, the tunneling amplitudes δA and δB, as well as the inter-dot interaction strength V, to investigate how these key parameters govern the generation, stabilization, and decay of quantum resources within the system. The obtained results reveal that, for both initial states, fractional dynamics with a low τ rapidly generates entanglement expecting maximal values LN≈1 and non-classical correlations quantified by local quantum uncertainty. Conversely, higher values of τ lead to slower entanglement but memory effects allow quantum resources to remain significant for a longer time, with the negativity remaining above (≈0.6). We also find that higher interaction frequencies V accelerate correlations and stabilize coherence, while a strong tunneling asymmetry degrades entanglement and coherence despite the initial benefits of increasing quantum resources.
A fractional quantum state has created between two-qubit system by a Heisenberg XYZ model in the presence of the Dzyaloshinskii–Moriya (DM) interaction. The impact of the initial state settings and the interaction parameters on the amount of the quantum correlation is discussed. We used the concurrence and local quantum uncertainty to quantify these correlations. It is shown that, both quantifiers increase suddenly/gradually depending on the order of the fractional state, and whether the system is ferromagnetic or anti-ferromagnetic. The fractional parameter may increase/ stabilized the memory of the generated fractional state. Small values of the DM interaction can maximize the initial quantum correlation of a partial entangled state. The possibility of using these fractional time-dependent states as quantum channels to perform quantum teleportation has examined. It is shown that, preparing the system in anti-ferromagnetic regime improves the fidelity of the teleported state. The strength of the DM interaction and the fractional’s order has a clear effect on the fidelity’s behavior, where they may be used as control parameters to increase the efficiency of the fractional quantum channel in the context of quantum communication.
Abstract This research delves into the dynamical behavior of quantum correlations and coherence within a mixed Heisenberg dimer system under the intrinsic decoherence. Our approach involves the application of logarithmic negativity, local quantum uncertainty, and the ℓ 1 norm-based coherence as quantifiers for entanglement, skew information correlations, and quantum coherence in this qubit-qutrit model. Our primary objective is to explore the impact of various factors on the dynamics of quantum correlations and quantum coherence. These factors encompass the initial density matrix and its mixing parameter, the intrinsic decoherence rate (γ), the external magnetic field, as well as intrinsic system parameters, notably the XXZ and uniaxial single-ion anisotropies. Our results demonstrate that the introduction of intrinsic decoherence (ID) significantly erodes quantum resources. Particularly, for high values of the ID rate (γ), excessive damping occurs, leading to the absence of oscillations or a rapid decay of quantum resources, ultimately stabilizing in steady states. Furthermore, the presence of an external homogeneous magnetic field further diminishes quantum resources within the system. However, despite the degradation induced by the combined influence of intrinsic decoherence and high external magnetic field intensities, the judicious selection of the initial density matrix and precise adjustment of the uniaxial single-ion anisotropy enable the preservation of quantum resources within the mixed spin-(1/2, 1) Heisenberg dimer.
We investigate the dynamics of key quantum correlations - Negativity (NG), Quantum Discord (QD), and Quantum-Memory-Assisted Entropic Uncertainty (QM-EUR) - in a bipartite two-qubit system under the influence of external pulses and various decoherence channels, including amplitude damping (gamma_amp), pure dephasing (gamma_deph), and pulse-induced dephasing (G), while different regimes of inter-qubit coupling (Jzz, Jxx), qubit energy splitting (epsilon), and pulse parameters (A_pulse, beta_pulse) are explored. Our results show that inter-qubit coupling and energy splitting epsilon significantly influence the dynamics, producing pronounced oscillations in the weak-coupling regime and protecting pre-existing entanglement in the strong-coupling regime. NG is the most sensitive, QD persists longer revealing nonclassical correlations independent of entanglement, and QM-EUR reflects residual quantum memory and entropic uncertainty, showing that quantum signatures survive even when NG and QD are weak. Pulse amplitude and width effectively control the generation and dissipation of correlations, while the intensity of pulse-induced dephasing modulates the balance between sustained oscillations and rapid decoherence. The initial state also plays a crucial role: a partially entangled initial state is more resilient to perturbations, preserving correlations over time, whereas a separable state exhibits cycles of entanglement creation and destruction. Thus, by adjusting system parameters, it is possible to control the stability and lifetime of correlations and coherence, providing a framework to optimize quantum systems for applications requiring both strong entanglement and long-lasting coherence, such as quantum computing and secure communication.
Abstract This study investigates the dynamics of quantum coherence and entanglement in the spin‐1 Heisenberg XXZ model. Particularly, the effects of the Heitler‐London (HL) coupling and the Dzyaloshinskii‐Moriya (DM) interaction are examined. By utilizing tools from quantum information theory, the concept of quantum correlated coherence and negativity are explored. The results show intrinsic decoherence leads to a decay of both correlated coherence and negativity. Interestingly, it is found that a small value of the Dzyaloshinskii‐Moriya interaction can significantly enhance coherence and entanglement. Various factors influence the system dynamics, including the initial state, anisotropy parameter, and the coupling distance between spins. It is shown that, by fixing the anisotropy parameter, the isotropic Heisenberg models XX and XXX can be easily recovered. Ultimately, the findings highlight that the system maintains a coherent temporal evolution despite decoherence.