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In this article, we theoretically study, in an atomic-optomechanical system, quantum correlations shared between three modes, namely mechanical mode, optical mode and atomic mode. We firstly investigate the combined effect of the variation of the cavity-collective atomic mode coupling and the effective optomechanical one, on the tripartite entanglement behavior as well as on tripartite steering evolution. Then, we discuss pairwise entanglement and bipartite steering according to the aforementioned couplings. Consequently, besides monogamy of the entanglement distribution, the sharing of Gaussian steering is also monogamous, thus the CKW-type monogamy inequalities are fully satisfied under all permutations of the three considered modes in a chosen stable region. In addition, the study of tripartite entanglement and tripartite steering behaviors leads to know the optimal conditions to generate genuine tripartite entanglement, one-way and two-way steering. [ABSTRACT FROM AUTHOR]

In this manuscript, we investigate the enhancement of the transfer of quantum correlations from squeezed light to movable mirrors within an optomechanical system. This enhancement was achieved via the injection of squeezed light in the cavities and via intracavity squeezed light. We quantify the entanglement between mechanical oscillators via logarithmic negativity. We demonstrate that entanglement is influenced by various factors, including the gain of the parametric amplifier, the squeezing parameter characterizing the squeezed light, the rate of the phonon tunneling process, the coupling strength of the photon hopping process and the bath temperature of the mechanical oscillators. We have shown that entanglement can be improved by a convenient choice of coupling strength in the case of the photon hopping process, as well as for specified values of the gain of the parametric amplifier. [ABSTRACT FROM AUTHOR]

In this work, the study focuses on an optomechanical system composed of two Fabry–Pérot cavities each pumped by a coherent laser source, and coupled by photon hopping process, phonon tunneling and by a squeezed light source. We theoretically investigate the impact of increasing the squeezing parameter of squeezed light on the sharing of quantum correlations between two mechanical modes and an optical mode, then between two optical modes and a mechanical mode using logarithmic negativity. Then, we study the effect of different couplings on the emergence and degree of tripartite entanglement by tripartite negativity. As a result, the entanglement shared in each considered three-mode block is monogamous and during the evolution the one-mode versus one-mode entanglement always remains less than one-mode versus two-mode entanglement. Moreover, the combined effect of different couplings can enhance tripartite entanglement in certain conditions as it can degrade it in other ones. Our results indicate that the proposal systems could provide an important platform for the study of macroscopic quantum phenomena. [ABSTRACT FROM AUTHOR]

In this paper, we present a coherent feedback loop scheme to enhance the magnon–photon–phonon entanglement in cavity magnomechanics. We provide a proof that the steady state and dynamical state of the system form a genuine tripartite entanglement state. To quantify the entanglement in the bipartite subsystem and the genuine tripartite entanglement, we use the logarithmic negativity and the minimum residual contangle, respectively, in both the steady and dynamical regimes. We demonstrate the feasibility of our proposal by implementing it with experimentally realizable parameters to achieve the tripartite entanglement. We also show that the entanglement can be significantly improved with coherent feedback by appropriately tuning the reflective parameter of the beam splitter and that it is resistant to environmental thermalization. Our findings pave the way for enhancing entanglement in magnon–photon–phonon systems and may have potential applications in quantum information. [ABSTRACT FROM AUTHOR]

We study the transfer of quantum correlations between two movable mirrors of two Fabry-Pérot cavities separated via broadband squeezed light and coupled via photon hopping process. We investigate the transfer of quantum correlations from EPR entangled squeezed light to the movable mirrors. We show that Gaussian quantum steering remains lower than entanglement. We employ Gaussian quantum steering to characterize the steerability between the two mechanical modes. The logarithmic negativity is used as the witness of quantum entanglement and Gaussian quantum discord gives the measure of all non classical correlations including entanglement. We conclude that the transfer of quantum correlations is optimal for a strong optomechanical coupling and decreases with the thermal effects. We also conclude that steering, entanglement and discord are directly related to photon hopping coupling and the squeezing parameter. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the present paper is the quantification of non-classical correlations between mechanical and optical modes in an optomechanical system with two spatially separated Fabry-Pérot cavities, using resolver sideband regime. To measure the amount of stationary entanglement, we use the criterion of Reid et al, while the evolution of the Gaussian quantum steering and its asymmetry make it possible to study the steerability of the correlations transfer between the different modes. Then, a theoretical study of the robustness of the Gaussian geometric discord (GGD), with respect to the temperature of the environment, is realized, for the two-mode symmetrical squeezed thermal states, to quantify quantum correlations beyond entanglement between mechanical and optical modes. By considering recent experimental parameters, we show that GGD is more robust than entanglement for a high thermal bath temperature. Finally, we find that these three indicators of quantumness enhance with the increase of the squeezing parameter. Graphical abstract: [ABSTRACT FROM AUTHOR]