In this work, we study the dynamics of global quantum discord and quantum Fisher information in a multipartite system of two-level atoms interacting with a coherent field. The model includes parametric amplification, Kerr-type nonlinearity, and intrinsic decoherence to examine how these effects control quantum correlations and parameter-estimation sensitivity. The results show that, without intrinsic decoherence, both quantities exhibit rapid oscillations with clear collapse and revival behavior. Strong Kerr nonlinearity and strong parametric amplification enhance global quantum discord, while quantum Fisher information becomes maximum under a suitable balance of Kerr nonlinearity and amplification strength. Increasing the number of atoms generally strengthens global quantum discord but does not always improve quantum Fisher information. Intrinsic decoherence damps the oscillations and drives the system toward steady-state behavior.
In this work, we study the dynamics of global quantum discord and quantum Fisher information in a multipartite system of two-level atoms interacting with a coherent field. The model includes parametric amplification, Kerr-type nonlinearity, and intrinsic decoherence to examine how these effects control quantum correlations and parameter-estimation sensitivity. The results show that, without intrinsic decoherence, both quantities exhibit rapid oscillations with clear collapse and revival behavior. Strong Kerr nonlinearity and strong parametric amplification enhance global quantum discord, while quantum Fisher information becomes maximum under a suitable balance of Kerr nonlinearity and amplification strength. Increasing the number of atoms generally strengthens global quantum discord but does not always improve quantum Fisher information. Intrinsic decoherence damps the oscillations and drives the system toward steady-state behavior.
In this paper, we investigate the interplay between quantum correlations, quantified by global quantum discord (GQD), and quantum Fisher information (QFI) within a multipartite two-level system interacting with a single-mode Fock field. Our model incorporates Kerr-like nonlinearity, parametric amplification, and intrinsic decoherence. By varying the photon-number cutoff, system dimensionality, and parametric amplification strength under different magnitudes of the Kerr effect, we analyze how these factors influence correlation dynamics and parameter estimation precision. We observe a threshold-like behavior in the photon number during the transition from a decoherence-dominated regime to a coherence-enhanced regime. These results show a balance between the amplification strength and Kerr effects, and reveal that GQD and QFI exhibit different levels of robustness. These findings provide valuable insights for optimizing nonlinear atom-field configurations in quantum information and quantum metrology applications.
This paper investigates the evolution of global quantum discord (GQD) and quantum Fisher information (QFI) of the interaction of multiple two-level atomic systems (TLS) with a single thermal field mode and a non-linear Kerr medium (NLKM) considering the cases of intrinsic decoherence and its absence. Results indicate that increasing the number of atomic systems (N) while maintaining the NLKM parameter constant ? leads to higher GQD and QFI values for both intrinsic intrinsic decoherence cases. With rising ?, the GQD values decrease but the oscillation rate of the GQD increases. The presence of intrinsic decoherence does not significantly reduce the GQD quasi-static value compared to the no-decoherence scenario for certain ? values. At the same time, a different trend is observed for higher ? values. The average QFI value rises with reduced oscillation amplitudes for higher ? values and larger N subsystems. Unlike the GQD, higher ? values aid in maintaining average QFI in the presence of intrinsic decoherence. For moving TLS, changing ? does not alter the oscillation periods of the GQD and QFI. The GQD values decrease with increased ? in the moving system case, while the QFI improves with higher ? values. Additionally, higher average thermal photons within the system suppress the GQD and QFI values and decrease oscillation amplitudes for both quantifiers.
In this paper, we explore the dynamics of the global quantum discord (GQD) and quantum Fisher information (QFI) of a multipartite two-level stationary and moving atomic system under the Stark shift effect. The system interacts with a thermal field with a different number of average thermal photons. For a fixed Stark parameter value, the GQD magnitudes increase as the system size (N) increases for both static and moving atomic systems. However, in the instance of a stationary atomic system and lower Stark parameter values, the QFI preserves a constant magnitude for different N values. When atomic motion is taken, the quantifier dynamics exhibit periodic oscillations. Additionally, increasing the Stark parameter led to a suppression in the magnitude of both GQD and QFI. With in the sight of intrinsic decoherence (ID), the quantifiers show a damping in their oscillations. Interestingly, the atomic motion assists to mitigate the damping effects caused by ID. Moreover, if the average thermal photons are increased, the magnitude of the GQD and QFI are decreased.
We have computed the global quantum discord (GQD) and von Neumann entropy (VNE) of multipartite two-level atomic systems interacting with a single-mode Fock field. We use Tavis–Cumming model. We have explored how quantum correlations and quantum entanglement evolve with time in such systems. The quantum system is prepared initially in a mixed state and different parameters are varied to see how they affect the information processing in the system. The dynamical character of the GQD and VNE show an interplay between classical and nonclassical correlations. Photons in this model play an important role to assist the GQD and VNE and we observed that the effects of the field on the GQD and VNE reside in the time evolution of the system indicating that both atom and field states have become entangled. The GQD is assisted in a nonlinear fashion with the number of photons in the system. The GQD and VNE show linear behavior with each other in the dynamics of the system. The effects of intrinsic decoherence on the dynamics of the GQD and VNE are also studied. We have extrapolated the results for a large photon number on the system. We have studied the effect of the change in the size of the system on the maximum value of GQD and VNE and we have estimated the scaling coefficients for this behavior.
This study investigates the quantum dynamics of three-level Stark-shifted atomic systems under the influence of a Nonlinear Kerr Medium (NLKM), focusing on the interplay between Quantum Fisher Information (QFI), Von Neumann Entropy (VNE), and photon-mediated interactions. By analyzing the temporal evolution of QFI (quantifying parameter estimation precision) and VNE (measuring quantum entanglement (QE), we demonstrate how Kerr nonlinearity (χ), Stark shifts (β), phase (ϕ), and photon numbers govern system behavior. Key findings reveal that lower χ values (e.g., [Formula: see text]) induce oscillatory QFI decay and rapid VNE growth, driven by atomic motion and NLKM interactions, with QFI peaks inversely correlated to VNE dips. Higher [Formula: see text] stabilizes both metrics, suppressing decoherence and entanglement fluctuations. Elevated photon numbers enhance stability by strengthening field-atom correlations, reducing oscillation amplitudes (particularly at low χ), and mitigating quantum fluctuations. The Stark effect (SE) amplifies energy-level shifts, while phase adjustments introduce asymmetries in quantum interference. These results highlight the system's tunability via [Formula: see text], and photon density. They position it as a versatile platform for quantum metrology and information processing, where precision, entanglement stability, and photon-mediated coherence are critical. Kerr interactions suppress long-time coherence and entanglement, while when [Formula: see text], Stark shifts can induce mild, transient quantum correlations. These dynamics are essential for controlling entanglement in cavity QED systems, especially when precise metrological performance is desired.
A two-level atom interacting with two nonlinear Kerr oscillators pumped by an optical parametric process is studied. An analytical solution for the dynamical evolution of an interaction between Su(1,1) and Su(2)-systems is derived. The role of intrinsic damping, detuning, and Kerr-like medium on the entanglement evolution, quantum correlation, and coherence is elucidated. It is shown that the intrinsic decoherence leads to the sudden death and sudden birth entanglement, while the detuning eradicates these effects. The quantum coherence growth can be controlled by the detuning and the Kerr-like medium.