Abstract The practical implementation of quantum information protocols is critically hindered by decoherence, which degrades essential quantum correlations. This paper investigates the dynamics of quantum correlations and the fidelity (FID) of quantum teleportation in a two-qubit system described by an anisotropic XXZ -Heisenberg model with the inclusion of bond-dependent Kitaev interactions and an external magnetic field. We model the system’s evolution under a dephasing noise channel using the Lindblad master equation formalism. The performance is quantified by tracking geometric quantum discord (GQD), (quantum mutual information, entanglement entropy (EE, and teleportation FID. Our numerical simulations reveal a rich interplay between the system’s internal Hamiltonian parameters and the external environment. We find that strong Heisenberg coupling ( J ) can induce periodic revivals of quantum correlations and FID, creating transient windows for robust protocol execution. Conversely, while moderate Kitaev interactions can help preserve non-classical correlations, strong Kitaev terms accelerate decoherence. The decoherence rate ( γ ) is identified as the most dominant factor, with a clear threshold beyond which quantum resources are rapidly lost. These findings provide crucial insights into engineering and controlling quantum spin systems to optimize their performance in noisy, real-world environments.
Abstract The practical implementation of quantum information protocols is critically hindered by decoherence, which degrades essential quantum correlations. This paper investigates the dynamics of quantum correlations and the fidelity (FID) of quantum teleportation in a two-qubit system described by an anisotropic XXZ -Heisenberg model with the inclusion of bond-dependent Kitaev interactions and an external magnetic field. We model the system’s evolution under a dephasing noise channel using the Lindblad master equation formalism. The performance is quantified by tracking geometric quantum discord (GQD), (quantum mutual information, entanglement entropy (EE, and teleportation FID. Our numerical simulations reveal a rich interplay between the system’s internal Hamiltonian parameters and the external environment. We find that strong Heisenberg coupling ( J ) can induce periodic revivals of quantum correlations and FID, creating transient windows for robust protocol execution. Conversely, while moderate Kitaev interactions can help preserve non-classical correlations, strong Kitaev terms accelerate decoherence. The decoherence rate ( γ ) is identified as the most dominant factor, with a clear threshold beyond which quantum resources are rapidly lost. These findings provide crucial insights into engineering and controlling quantum spin systems to optimize their performance in noisy, real-world environments.
In this paper, we propose a model to describe the geometry of quantum correlations and entanglement through their distinct physical significance in quantum information processing and modern communications. However, geometric discord, using trace, Hilbert–Schmidt distances, and entanglement of formation, is engineered to be a well-defined non-classical correlation measure of an atomic field system. It consists of employing Jaynes–Cummings model to study the interaction between an excited atom at two levels and a single electromagnetic field mode inside an electrodynamic cavity in two cases, namely resonance and non-resonance. In fact, the dynamics of these measures depends decisively on the atom-field initial parameters where, importantly, the field parameters can be specified as control settings to implement an optimal teleportation protocol. The obtained results reveal that the behaviors of teleported geometric quantum discord and entanglement are similar to those displayed for maximum fidelity in terms of fully entanglement fraction. Therefore, since fidelity always exceeds the classical limit, one can design a quantum teleportation scheme with robust fidelity superior to any conventional communication protocol.
The entanglement dynamics of an anisotropic two-qubit Heisenberg XYZ system in the presence of intrinsic decoherence is studied. The usefulness of such system for performance of the quantum teleportation protocol T0 and entanglement teleportation protocol T1 is also investigated. The results depend on the initial conditions and the parameters of the system. For the product and maximally entangled initial states, increasing the size of spin-orbit interaction parameter D amplifies the effects of dephasing and hence decreases the asymptotic entanglement and fidelity of teleportation. We show that the XY and XYZ Heisenberg systems provide a minimal resource entanglement, required for realizing efficient teleportation. Also, we find that for the some special cases there are some maximally entangled states which are immune to intrinsic decoherence. Therefore, it is possible to perform the quantum teleportation protocol T0 and the entanglement teleportation T1 with perfect quality by choosing a proper set of parameters and employing one of these maximally entangled robust states as initial state of the resource.
In distributed quantum computing, quantum networks provide a potential infrastructure for long-range quantum information processing. Controlled quantum teleportation (CQT) is a key practically relevant protocol that can connect two parties on a network and enables a third party, the controller to allow or abort the secure teleportation of an arbitrary single-qubit state between the two parties. We investigate the robustness of a three-qubit GHZ resource under bit-flip, phase-flip, depolarizing, and amplitude-damping noise. Using the Kraus-operator formalism, we characterize the noisy resource through multipartite quantum discord, genuine multipartite concurrence (GMC), localizable entanglement (LE), and CQT fidelity. We also outline a proof-of-concept photonic implementation for preparing the three-qubit GHZ resource and realizing the CQT protocol, which could enable experimental investigation of the effects of noise. Our results show that bit-flip and amplitude-damping noise generally preserve useful mutipartite quantum correlations over broader noise parameter ranges. Interestingly, multipartite discord exhibits freezing under bit-flip noise over a finite parameter regime. Moreover, discord can persist beyond the sudden death of genuine multipartite entanglement, revealing the distinct robustness of nonclassical correlations. We further demonstrate that CQT fidelity which characterizes the performance of CQT can exceed the classical threshold even after GMC vanishes, while LE more closely reflects the operational usefulness of the noisy resource. These findings highlight the complementary roles of quantum correlations and entanglement in assessing the resilience of GHZ-based protocols.
In this paper, we investigate the time evolution of quantum correlations in a two-qubit system influenced by an optical channel. The system?s dynamics are analyzed in terms of concurrence (CN), Bell non-locality (BN), and trace distance discord (TDD), which quantify entanglement, non-local correlations, and quantum discord, respectively. Our model explores the impact of key parameters such as the beam-splitter angle, ?, channel parameter, ?, and angular frequency, ?, on these quantum correlations. The results show that CN and BN exhibit oscillatory behavior with periodic revivals, but tend to decay more rapidly under noisy conditions. Conversely, TDD demonstrates greater robustness, persisting even when CN and BN collapse, indicating the survival of quantum correlations in separable states. Higher noise strength and angular frequencies induce faster oscillations and revivals across all measures, with systems prepared with stronger initial quantum correlations showing increased resilience. This study highlights the robustness of quantum discord in noisy environments and its potential role in quantum information processing, even in the absence of entanglement.
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.
Characterizing quantum correlations and quantum teleportation in gg→ttˉ and qqˉ→ttˉ processes under noisy channels
The measurement of top-quark spin correlations provides a key tool for probing its interactions with high precision. Owing to its extremely short lifetime (τ∼10−25 s), the top quark preserves its spin polarization information, making the ttˉ system an ideal framework for investigating quantum correlations in high-energy physics. In this work, we analyze quantum correlations in ttˉ pairs produced in QCD using several quantum information-theoretic measures, including Bell nonlocality, quantum steering, concurrence, and geometric quantum discord. Their dependence on kinematic variables is examined in both the gg→ttˉ and qqˉ→ttˉ channels, with convergence toward the gg→ttˉ dominated regime in the ultra-relativistic limit (β=1). We also investigate the effect of three effective decoherence channels (AD, PD, and PF). The AD and PD channels lead to a monotonic degradation of correlations as the decoherence parameter p increases, while the PF channel exhibits a symmetric behavior around p=1/2. The impact of these channels on quantum teleportation is analyzed, showing that it remains above the classical threshold of 2/3 even in the presence of noise. These results indicate that certain quantum resources can persist despite decoherence, opening new perspectives at the interface of quantum information and particle physics.