This work investigates the emergence of Non-classical Features in a pump-free hybrid atom-optomechanical system, addressing key limitations of conventional platforms that rely on strong coherent driving and are highly vulnerable to thermal decoherence. We propose a novel architecture in which a squeezed vacuum reservoir acts as a pre-correlated quantum environment, enabling the deterministic generation and stabilization of nonclassical correlations without the need for an external laser pump. By exploiting reservoir-engineered interactions, the system supports robust quadrature squeezing and multipartite entanglement across a wide range of operational parameters. Our analysis demonstrates that the hybrid system achieves significant squeezing levels approaching 90%, while simultaneously satisfying the DGCZ inseparability criterion, confirming the presence of strong continuous-variable entanglement. Importantly, these nonclassical signatures remain resilient under extreme thermal conditions, withstanding thermal occupancies as high as (nth = 1500), which substantially exceeds the tolerance of traditional laser-driven optomechanical systems. The underlying mechanism is attributed to passive correlation injection from the engineered reservoir, which effectively suppresses thermal noise and enhances quantum coherence even in weak-coupling and low-power regimes. This eliminates the need for active pumping, thereby reducing energy consumption and experimental complexity. Furthermore, the hybrid atom-optomechanical configuration introduces additional tunability through atomic gain and population inversion, thereby allowing flexible control over system dynamics and correlation properties. Overall, the proposed scheme establishes a scalable and energy-efficient pathway toward realizing robust quantum correlations in realistic noisy environments. It opens new prospects for cryogen-free quantum technologies, including quantum-enhanced sensing, precision metrology, and long-distance entanglement distribution.
This work investigates the emergence of Non-classical Features in a pump-free hybrid atom-optomechanical system, addressing key limitations of conventional platforms that rely on strong coherent driving and are highly vulnerable to thermal decoherence. We propose a novel architecture in which a squeezed vacuum reservoir acts as a pre-correlated quantum environment, enabling the deterministic generation and stabilization of nonclassical correlations without the need for an external laser pump. By exploiting reservoir-engineered interactions, the system supports robust quadrature squeezing and multipartite entanglement across a wide range of operational parameters. Our analysis demonstrates that the hybrid system achieves significant squeezing levels approaching 90%, while simultaneously satisfying the DGCZ inseparability criterion, confirming the presence of strong continuous-variable entanglement. Importantly, these nonclassical signatures remain resilient under extreme thermal conditions, withstanding thermal occupancies as high as (nth = 1500), which substantially exceeds the tolerance of traditional laser-driven optomechanical systems. The underlying mechanism is attributed to passive correlation injection from the engineered reservoir, which effectively suppresses thermal noise and enhances quantum coherence even in weak-coupling and low-power regimes. This eliminates the need for active pumping, thereby reducing energy consumption and experimental complexity. Furthermore, the hybrid atom-optomechanical configuration introduces additional tunability through atomic gain and population inversion, thereby allowing flexible control over system dynamics and correlation properties. Overall, the proposed scheme establishes a scalable and energy-efficient pathway toward realizing robust quantum correlations in realistic noisy environments. It opens new prospects for cryogen-free quantum technologies, including quantum-enhanced sensing, precision metrology, and long-distance entanglement distribution.
We theoretically study a multimode nonequilibrium optomechanical system coupled to squeezed-vacuum and thermal reservoirs, focusing on the interplay between quantum coherence, dissipation, and heat transport. Using covariance-matrix methods, we analyze bipartite entanglement, EPR steering, and energy currents in the steady state. We show that weak optomechanical coupling preserves squeezing-induced entanglement, whereas strong coupling enhances phonon-mediated decoherence and suppresses quantum correlations. The system exhibits one-way quantum steering, indicating directional quantum information transfer. We further demonstrate that reservoir squeezing acts as a nonclassical energy source that sustains nonequilibrium heat flow, while substrate-mediated phonon correlations generate geometry-dependent thermal rectification controlled by the separation between mechanical resonators. Interference between transport pathways can strongly suppress heat currents, analogous to dark-state effects in quantum optics. These findings provide a unified framework linking squeezing, entanglement, steering, and heat transport, with potential applications in quantum thermal devices, phononic routing, and heat-resilient quantum technologies.
Quantum entanglement and squeezing associated with the motions of massive mechanical oscillators play an essential role in both fundamental science and emerging quantum technologies, yet realizing such macroscopic nonclassical states remains a formidable challenge. In this paper, we investigate how to achieve strong optomechanical entanglement and mechanical squeezing in a membrane-embedded cavity optomechanical system incorporating a coherent feedback loop, where the membrane interacts with the cavity mode through both linear and quadratic optomechanical couplings. This hybrid optomechanical architecture offers a flexible tunability of intrinsic system parameters, thereby enabling controlled stiffening or softening of the mechanical mode through adjusting quadratic optomechanical coupling, as well as effective modulation of the cavity decay rate via feedback control. More importantly, the synergistic interplay effect allows for a strategic reconfiguration of the system's stability regime, which in turn permits the presence of significantly enhanced effective optomechanical coupling strengths before entering the unstable regime. Exploiting these unique features, we demonstrate that optomechanical entanglement can be substantially enhanced with positive coupling sign and suitable feedback parameters, while strong mechanical squeezing beyond the 3dB limit is simultaneously achieved over a broad parameter range with negative coupling sign, reaching squeezing degree above 10dB under optimized conditions. Our proposal, establishing an all-optical method for generating highly entangled or squeezed states in cavity optomechanical systems, opens up a new route to explore macroscopic quantum effects and to advance quantum information processing.
Quantum entanglement and squeezing associated with the motions of massive mechanical oscillators play an essential role in both fundamental science and emerging quantum technologies, yet realizing such macroscopic nonclassical states remains a formidable challenge. In this paper, we investigate how to achieve strong optomechanical entanglement and mechanical squeezing in a membrane-embedded cavity optomechanical system incorporating a coherent feedback loop, where the membrane interacts with the cavity mode through both linear and quadratic optomechanical couplings. This hybrid optomechanical architecture offers a flexible tunability of intrinsic system parameters, thereby enabling controlled stiffening or softening of the mechanical mode through adjusting quadratic optomechanical coupling, as well as effective modulation of the cavity decay rate via feedback control. More importantly, the synergistic interplay effect allows for a strategic reconfiguration of the system's stability regime, which in turn permits the presence of significantly enhanced effective optomechanical coupling strengths before entering the unstable regime. Exploiting these unique features, we demonstrate that optomechanical entanglement can be substantially enhanced with positive coupling sign and suitable feedback parameters, while strong mechanical squeezing beyond the 3dB limit is simultaneously achieved over a broad parameter range with negative coupling sign, reaching squeezing degree above 10dB under optimized conditions. Our proposal, establishing an all-optical method for generating highly entangled or squeezed states in cavity optomechanical systems, opens up a new route to explore macroscopic quantum effects and to advance quantum information processing.
Squeezed thermal reservoirs, characterized by thermal noise with anisotropic fluctuations, have profound implications in quantum thermodynamics and serve as powerful resources for quantum information. However, their experimental realizations remain challenging. Existing schemes typically rely on injected squeezed light, time-dependent modulation, or driven nonlinear interactions, which introduce complexity and limit experimental feasibility. Using only time-independent linear coupling to a lossy mode within a normal thermal environment, we identify a general and experimentally accessible framework for squeezed-reservoir engineering, applicable across platforms such as circuit and cavity quantum electrodynamics as well as coupled cavity systems. We illustrate the framework through two experimentally relevant cases: directional phase coherence extension in two-level systems like qubits or atoms, and dissipative quadrature squeezing in bosonic modes like photons or phonons. By eliminating the need for active control or squeezed input, our passive linear-coupling approach provides a resource-efficient and practical pathway to dissipative squeezing, decoherence suppression, entanglement stabilization, quantum simulation, and the exploration of unconventional quantum thermodynamics and phase transitions.
Quantum optomechanical systems enable versatile control of non-classical light. We study two-mode squeezed-light generation in a driven optomechanical cavity with parametrically amplified optical modes coupled to mechanical resonator. Coherent driving reveals a rich control landscape where parametric nonlinearity, optomechanical coupling, and reservoir interactions jointly tailor quantum correlations-including two-mode squeezing, entanglement, steering, and discord. Remarkably, mechanical oscillators not only mediate optical entanglement but also act as a squeezing resource, enabling enhancement or suppression of quantum correlations via parameter tuning. We derive steady-state second-order moments and closed-form covariance matrix expressions, quantifying entanglement via logarithmic negativity, steering via Reid criterion, and discord via von Neumann entropy, providing a comprehensive framework for optimized generation of quantum correlations in hybrid quantum systems.
Abstract Quantum technologies critically rely on maintaining coherence and controllable correlations in open systems, yet these resources are fragile under dissipation and noise. To address this challenge, we investigate a hybrid platform composed of two identical three-level atoms in a V-type configuration coupled to a single-mode cavity field prepared in a squeezed coherent state. Using the Lindblad master equation, we numerically simulate the system dynamics, allowing a rigorous treatment of coherent atom–field interactions, interatomic couplings, and cavity losses. Our analysis reveals that squeezing introduces nonclassical correlations that enhance field coherence and support the generation of entanglement under specific regimes. Strong interatomic coupling stabilizes entanglement, while squeezing mitigates decoherence-induced losses. Conversely, large photon amplitudes and cavity dissipation degrade both coherence and bipartite correlations. Quantum steering emerges as the most fragile correlation, yet its persistence can be moderately extended through squeezing. These results identify squeezing and interatomic interactions as complementary resources for optimizing coherence, entanglement, and steering, offering practical strategies for robust quantum communication, information processing, and engineered nonclassical states.