Abstract We present a comprehensive study of quantum coherence dynamics in a qubit–qutrit system coupled to a resonator and exposed to an external noisy environment. Unlike prior works, we focus on the comparative analysis of three distinct coherence measures–l 1-norm of coherence, relative entropy of coherence, and Jensen–Shannon coherence–under dynamic modulation of the resonator frequency. Our key innovation lies in introducing time-dependent sinusoidal and standing wave modulations to the oscillator frequency, revealing nontrivial effects on coherence preservation that are highly sensitive to the modulation parameters. Remarkably, we uncover parameter regimes where coherence revivals are enhanced, even under strong decoherence, a phenomenon not observed in static systems. Additionally, our results demonstrate distinct sensitivity patterns among the coherence measures, highlighting their complementary roles in capturing system-environment interactions. This reanalysis is crucial as it reveals previously unexplored mechanisms for coherence control in hybrid quantum systems, offering novel strategies for improving the robustness of quantum technologies against environmental disturbances.
Abstract We present a comprehensive study of quantum coherence dynamics in a qubit–qutrit system coupled to a resonator and exposed to an external noisy environment. Unlike prior works, we focus on the comparative analysis of three distinct coherence measures–l 1-norm of coherence, relative entropy of coherence, and Jensen–Shannon coherence–under dynamic modulation of the resonator frequency. Our key innovation lies in introducing time-dependent sinusoidal and standing wave modulations to the oscillator frequency, revealing nontrivial effects on coherence preservation that are highly sensitive to the modulation parameters. Remarkably, we uncover parameter regimes where coherence revivals are enhanced, even under strong decoherence, a phenomenon not observed in static systems. Additionally, our results demonstrate distinct sensitivity patterns among the coherence measures, highlighting their complementary roles in capturing system-environment interactions. This reanalysis is crucial as it reveals previously unexplored mechanisms for coherence control in hybrid quantum systems, offering novel strategies for improving the robustness of quantum technologies against environmental disturbances.
We study the dissipative dynamics of a hybrid qubit–qutrit system initially prepared in the interacting thermal (Gibbs) state of the full Hamiltonian and subsequently subjected to a non-Markovian amplitude-damping channel. To benchmark the persistence of nonclassical features in this noisy setting, we track four complementary quantum resources: entanglement via negativity (NEG), nonclassical correlations via geometric quantum discord (GQD), coherence via the [Formula: see text]-norm of coherence (LNC) and measurement-induced quantumness via local quantum uncertainty (LQU). We show that coherent exchange coupling g enhances both the initial magnitudes and lifetimes of all resources by strengthening qubit–qutrit hybridization, whereas strong dispersive (cross-Kerr) coupling [Formula: see text] suppresses thermal correlations already at [Formula: see text], thereby limiting the resources available before dissipation sets in. Environmental memory effects, controlled by the reservoir cutoff frequency, slow the decay and can induce some revival pattern–assisted decay, extending the operational time window slightly. Across a broad parameter range, coherence (LNC) is consistently the most robust resource, often persisting after entanglement and discord have decayed, indicating that coherence-based protocols may provide superior stability in noisy hybrid architectures.
ABSTRACT This research examines the dynamics of quantum correlations in a hybrid qubit–qutrit system subjected to an Ohmic noisy environment. While entanglement degradation in homogeneous systems is well‐documented, the behavior of disparate‐dimensional interfaces remains a critical challenge for the interoperability of future quantum networks. Using the negativity as a measure of entanglement, we analytically and numerically investigate how the spectral properties of the reservoir influence the system´s coherence. Our results reveal that the cut‐off frequency ω c acts as a fundamental control parameter: at low frequencies, it triggers non‐Markovian effects that effectively shield the system from entanglement sudden death, whereas high frequencies accelerate the transition to a purely dissipative regime. Furthermore, we demonstrate that strategic optimization of the coupling strength J and the entanglement parameter r can significantly enhance the robustness of hybrid correlations. The findings provide new methodological insights and practical guidelines for reservoir engineering, offering a framework to preserve quantum resources in high‐dimensional hybrid architectures.
Hybrid quantum systems integrating superconducting qubits and nitrogen-vacancy (NV) center qutrits are promising for quantum information processing but are vulnerable to environmental dephasing. This study investigates the distinct dynamical behaviors of three facets of quantumness — total nonclassical correlations (Local Quantum Uncertainty (LQU)), quantum superposition ([Formula: see text] norm of coherence), and entanglement (Negativity) — in such a qubit–qutrit hybrid system subjected to non-Markovian dephasing noise. We reveal a clear hierarchy of robustness: coherence exhibits remarkably persistent oscillations, LQU decays with damped oscillations to a stable non-zero baseline, while entanglement proves most fragile, suffering periodic sudden death. Our central finding is the uniquely constructive role of the direct qubit–qutrit coupling strength, which robustly enhances all three quantum resources. In contrast, most other system parameters either accelerate decoherence or have complex, non-monotonic effects. These results clarify the different resilience levels of quantum resources and identify key parameters for preserving quantumness in noisy hybrid systems.
Quantum dots are nanometer-scale semiconductor particles that exhibit size-dependent quantum mechanical properties. In this work, we investigate the dynamics of quantum correlations, quantified by the concurrence and the quantum coherence, in a bipartite system of coupled double quantum dots. The analysis is carried out within both Markovian and non-Markovian regimes, and further extended to different noisy quantum channels, including amplitude damping, phase flip, and phase damping. Our results show that environmental memory plays a crucial role in the preservation of quantum correlations, leading to oscillatory behavior and partial revivals in the non-Markovian regime, in contrast to the monotonic decay observed under Markovian dynamics. Moreover, distinct decoherence mechanisms induce qualitatively different effects: dissipative channels rapidly suppress correlations, while phase-based channels lead to either redistribution or gradual degradation. A key finding is that quantum coherence exhibits a higher robustness compared to entanglement under all considered conditions, highlighting its relevance as a reliable quantum resource in noisy environments. These results provide valuable insights into the control and protection of quantum correlations in realistic solid-state systems.
Abstract We investigate a hybrid qubit–qutrit system exposed to both a magnetic field and classical dephasing noise. The quantum system’s characteristics encompass diverse parameters, including spin-exchange interaction, dephasing, and the magnetic field. To incorporate thermal effects, we employ the system’s Hamiltonian to generate an initial qubit–qutrit density matrix within the framework of the Gibbs density operator. Furthermore, we model dephasing effects on the initial thermal state of the system using an Ornstein–Uhlenbeck process. We employ geometric discord, negativity, and entropic coherence functions to depict the quantum correlations across various parameter settings. Our results reveal that initially, quantum correlations attain non-maximal values, with their dynamics intricately reliant on the underlying system parameters. Specifically, when the system is primarily characterized by the magnetic field, we observe heightened levels of quantum correlations. Additionally, temperature-based characterization is found to have the most detrimental effect on the state. Geometric discord is observed to capture a higher degree of quantum correlations, albeit saturating rapidly at zero compared to entanglement and coherence. Finally, we investigated the effects of common environmental coupling and more pronounced non-Markovian dynamics in the system, revealing an enhanced preservation of quantum correlations. These modifications allow for prolonged coherence and entanglement, underscoring the potential of structured environmental interactions to mitigate decoherence effects and sustain quantum correlations over time.
Quantum coherence is a key resource underpinning quantum technologies, yet it is highly susceptible to environmental decoherence, especially in thermal settings. While frequency modulation (FM) has shown promise in preserving coherence at zero temperature, its effectiveness in realistic, noisy thermal environments remains unclear. In this work, we investigate a single frequency-modulated qubit interacting with a thermal phase-covariant reservoir composed of dissipative and dephasing channels. We demonstrate that FM significantly preserves coherence in the presence of thermal dissipation while being ineffective under thermal pure-dephasing noise due to commutation between system and interaction Hamiltonians. When both noise channels are present, FM offers protection only for weak dephasing coupling. Our findings clarify the limitations and potential of FM-based coherence protection under thermal noise, supplying practical insights into designing robust quantum systems for quantum applications.