The optomechanical cavity system has been a paradigm in the manifestation of continuous variable quantum information over the past decade. This paper investigates how quantum phase synchronization is associated with bipartite Gaussian entanglement in coupled gain-loss mechanical oscillators, where the gain and loss rates can be controlled by driving the cavities with blue and red detuned lasers, respectively. We examine the role of the exceptional point (EP) in a deterministic way of producing self-sustained oscillations that generate robust quantum correlations among quadrature fluctuations of the mechanical oscillators. Particularly, steady phase synchronization dynamics along with the entanglement phenomena are observed in the effective weak-coupling regime above a critical driving power. These phenomena are further verified by observing the mechanical squeezing and phase-space rotations of the Wigner distributions. Moreover, the fidelity fluctuation shows how the quantum correlation dynamics are related to the EP of the system. We also discuss the impact of the mechanical oscillator's frequency mismatch and decoherence due to thermal phonons on system dynamics. These findings hold promise for applications in phonon-based quantum communication and information processing on the macroscopic scale.
The optomechanical cavity system has been a paradigm in the manifestation of continuous variable quantum information over the past decade. This paper investigates how quantum phase synchronization is associated with bipartite Gaussian entanglement in coupled gain-loss mechanical oscillators, where the gain and loss rates can be controlled by driving the cavities with blue and red detuned lasers, respectively. We examine the role of the exceptional point (EP) in a deterministic way of producing self-sustained oscillations that generate robust quantum correlations among quadrature fluctuations of the mechanical oscillators. Particularly, steady phase synchronization dynamics along with the entanglement phenomena are observed in the effective weak-coupling regime above a critical driving power. These phenomena are further verified by observing the mechanical squeezing and phase-space rotations of the Wigner distributions. Moreover, the fidelity fluctuation shows how the quantum correlation dynamics are related to the EP of the system. We also discuss the impact of the mechanical oscillator's frequency mismatch and decoherence due to thermal phonons on system dynamics. These findings hold promise for applications in phonon-based quantum communication and information processing on the macroscopic scale.
Spontaneous synchronization is a significant collective behavior of weakly coupled systems. Due to their inherent nonlinear nature, optomechanical systems can exhibit self-sustained oscillations which can be exploited for synchronizing different mechanical resonators. In this paper, we explore the synchronization dynamics of two membranes coupled to a common optical field within a cavity, and pumped with a strong blue-detuned laser drive. We focus on the system quantum dynamics in the parameter regime corresponding to synchronization of the classical motion of the two membranes. With an appropriate definition of the phase difference operator for the resonators, we study synchronization in the quantum case through the covariance matrix formalism. We find that for sufficiently large driving, quantum synchronization is robust with respect to quantum fluctuations and to thermal noise up to not too large temperatures. Under synchronization, the two membranes are never entangled, while quantum discord behaves similarly to quantum synchronization, that is, it is larger when the variance of the phase difference is smaller.
In an optomechanical system (OMS), the dynamics of quantum correlations, e.g., quantum discord, can witness synchronized squeezing between the cavity and mechanical modes. We investigate an OMS driven by two coherent fields, and demonstrate that optimal quantum correlations and squeezing synchronization can be achieved by carefully tuning key parameters: the cavity-laser detunings, loss rates, and the effective coupling ratio between the optomechanical interaction and the amplitude drive. By employing the steady-state solution of the covariance matrix within the Lyapunov framework, we identify the conditions under which squeezing becomes stabilized. Furthermore, we demonstrate that synchronized squeezing of the cavity and mechanical modes can be effectively controlled by tuning the loss ratio between the cavity and mechanical subsystems. Alternatively, in the case where the cavity is driven by a single field, we demonstrate that synchronized squeezing in the conjugate quadratures of the cavity and mechanical modes can still be achieved, provided that the cavity is coupled to a squeezed reservoir. The presence of this engineered reservoir compensates the absent driving field, by injecting directional quantum noise, thereby enabling the emergence of steady-state squeezing correlations between the two modes. A critical aspect of our study reveals how the interplay between dissipative and driven-dispersive squeezing mechanisms governs the system’s bandwidth and robustness against decoherence. Our findings provide a versatile framework for manipulating quantum correlations and squeezing in OMS, with applications in quantum metrology, sensing, and the engineering of nonclassical states. This work advances the understanding of squeezing synchronization and offers new strategies for enhancing quantum-coherent phenomena in dissipative environments.
An optomechanical cavity driven by a periodically amplitude-modulated laser can generate steady light-mechanical entanglement with time periodicity. Similar results can be alternatively obtained by pumping an especially tuned optical degenerate parametric amplifier (DPA) inside the cavity. While the two laser beams are simultaneously applied, the optomechanical entanglement can exhibit constructive and destructive interference patterns, depending on their cooperative phase, which further gives rise to beating in entanglement dynamics if the two modulation frequencies are slightly different, followed by a beating frequency-dependent dynamical behavior in the energy exchange between light and a mechanical oscillator. The optimal dynamical entanglement goes beyond what is attainable by the scenario with two superimposed cavity drivings, as a result of the specially DPA-modulated quantum dynamics. Moreover, we calculate correlation spectra between the cavity and mechanical modes, and we find correspondence between the light-oscillator entanglement and the correlation spectra under the cooperative effect. The cooperation-enhanced optomechanical entanglement is robust against the thermal temperature, and is potentially useful for continuous variable quantum information processing.
This paper investigates the deterministic generation and coherent control of continuous-variable bipartite and tripartite entanglement within a multi-mirror electro-optomechanical ring cavity. The proposed architecture integrates radiation pressure with tunable Coulomb interactions, governed by external gate voltages, to establish quantum correlations between an intracavity optical field and a collective of four mechanical oscillators. We perform a rigorous stability analysis of the system, identifying the operational regimes across a broad range of free parameters, and evaluate the generation of tripartite entanglement within two distinct subsystems. Our numerical results demonstrate that while standard coherent driving combined with Coulomb coupling can generate entanglement, it is restricted to narrow detuning regions. In contrast, the introduction of squeezed light dramatically enhances quantum correlations, facilitating entanglement over a significantly wider range of normalized detuning without compromising the stability of the optomechanical system. A central finding is that the fixed charged body serves as a dynamic control parameter rather than a static component; by effectively tuning the mechanical susceptibility, it enables the generation of optomechanical entanglement that is both stronger and more resilient to thermal noise than the mechanical–mechanical entanglement mediated by direct Coulomb interaction. Furthermore, the external gate voltage provides a reliable mechanism for the continuous tuning of mechanical coupling strengths. From a practical perspective, the ability of the Coulomb coupling to act as a quantum switch for activating or suppressing entanglement suggests significant potential for quantum information control and state transfer within hybrid quantum architecture networks.
We present a proposal to generate robust optomechanical entanglement induced by the blue-detuning laser and the mechanical gain in a double-cavity optomechanical system. We show that the stability of the system can be obtained by introducing a cavity mode driven by the red-detuning laser in the blue-detuning regime. In contrast to the red-detuning regime, we find that the entanglement in the blue-detuning regime is extremely robust to temperature. The cavity mode driven by the blue-detuning laser can control indirectly the optomechanical entanglement between mechanical resonator and cavity mode driven by the red-detuning laser. Moreover, the entanglement between two cavity modes without direct coupling can also be achieved in our system. Although the entanglement is weak, it is robust to temperature, and meanwhile, the optomechanical entanglement is hardly affected by the temperature when the damping rate of the mechanical oscillator is close to zero. Furthermore, the entanglement amplification at high temperature can be achieved by adjusting the mechanical gain appropriately. Our proposal provides an efficient way to achieve robust optomechanical entanglement in the blue-detuning regime and entanglement amplification in optomechanical system with mechanical gain.
We present a systematic study on the effects of dynamical transfer and steady-state synchronization of quantum states in a hybrid optomechanical network consisting of two cavities, which carry atoms inside and interact via a common moving mirror such as the mechanical oscillator. It is found that a high fidelity transfer of Schrödinger’s cat and squeezed states between two cavities modes is possible. On the other hand, we demonstrate the synchronization effect of the cavity modes in a steady squeezed state with its high fidelity realized by the mechanical oscillator that intermediates the generation, transfer and stabilization of the squeezing. In this framework, we also study the generation and evolution of bipartite and tripartite entanglement and find its connection to the effects of quantum state transfer and synchronization. Particularly, when the transfer occurs at the maximal fidelity, any entanglement is almost zero, so the different cavity modes are disentangled. However, these modes become entangled when the two bosonic modes are synchronized in a stationary squeezed state. The results provided by the current study may find applications in quantum information technologies, in addition to the setups for metrology, where squeezed states are essential.