Quantum entanglement and quantum coherence generated from the optomagnomechanical system are important resources in quantum information and quantum computation. In this paper, a scheme for flexibly generating optomagnonic quantum entanglement and quantum coherence difference is proposed, based on a double-cavity-optomagnomechanical system. The parameter dependencies of the bipartite optomagnonic entanglement, the genuine tripartite optomagnonic entanglement, the quantum coherence difference, and the stability of the system, are investigated intensively. The results show that this scheme endows the magnon more flexibility to choose different mechanisms, under the condition of maintaining the system stable. This work is valuable for connecting different nodes in hybrid quantum networks and manipulating the magnon states with light in the future.
Quantum entanglement and quantum coherence generated from the optomagnomechanical system are important resources in quantum information and quantum computation. In this paper, a scheme for flexibly generating optomagnonic quantum entanglement and quantum coherence difference is proposed, based on a double-cavity-optomagnomechanical system. The parameter dependencies of the bipartite optomagnonic entanglement, the genuine tripartite optomagnonic entanglement, the quantum coherence difference, and the stability of the system, are investigated intensively. The results show that this scheme endows the magnon more flexibility to choose different mechanisms, under the condition of maintaining the system stable. This work is valuable for connecting different nodes in hybrid quantum networks and manipulating the magnon states with light in the future.
The optomagnomechanical system, which involves flexible nonlinearities, is one of the promising physical platforms for studying the preparation and manipulation of quantum entanglements, as well as the construction of hybrid quantum networks. A scheme for entanglement enhancement and quadripartite entanglement generation is proposed, based on a cascaded optomagnomechanical system. On the one hand, optomicrowave and optomagnonic entanglements within the two subsystems are investigated, and their parameter dependence, such as detuning, decay, coupling strength, transmission efficiency, and temperature is discussed. On the other hand, the parameter conditions for achieving optimal optomicrowave and optomagnonic quadripartite entanglements are also obtained. The results show that significant enhancement of optomicrowave and optomagnonic entanglements in the second cavity can be obtained in a certain range of parameters. Under optimized parameter conditions, optomicrowave and optomagnonic quadripartite entanglements can be generated throughout the entire cascaded system. This research provides a theoretical basis for the manipulation of quantum entanglement, the transmission of the magnon's state, and the construction of hybrid quantum networks involving different physical systems.
Flexible manipulation of quantum correlation resources enables the implementation of diverse quantum tasks based on hybrid quantum networks, where atom-magnon and optomagnonic entanglements and steerings play important roles. In this work, we propose an effective scheme to generate and manipulate quantum entanglements and steerings based on a hybrid optomagnomechanical system, which is composed of a polarizer, an optical cavity with YIG bridge as one end, and an atomic ensemble in it. According to the results of the parameter dependence of various quantum correlations, we can selectively generate bipartite and genuine tripartite entanglements and deterministically manipulate the concrete situation of bipartite, multipartite steerings, and collective pentapartite steering, by adjusting the polarization direction of the driving laser and the Tavis-Cummings coupling strength. Our all-optical controlled scheme is flexible, convenient, compact, and experimentally feasible, because multiple coupling channels can be tuned simultaneously. This work provides a new perspective for implementing specialized quantum tasks, such as hierarchical ultra-secure multi-user quantum communications.
Optomicrowave entanglement and optomagnonic entanglement have significant applications in constructing hybrid quantum network and optical controlling magnons. In this paper, a theoretical scheme of enhancing optomicrowave and optomagnonic entanglements is proposed, based on a coherent-feedback-assisted optomagnomechanical (OMM) system. By inserting a thin membrane between the input-output mirror and the high-reflective-mirror-attached YIG bridge, the system consists of four kinds of modes: optical mode, microwave mode, mechanical mode, and magnon mode. In this system, optical mode and microwave mode interact with each other through the mechanical mode, while the magnon mode couples with the microwave mode through magnetic-dipole interaction. The entanglement is originally generated between optical mode and phonon mode under the two-mode squeezing mechanism (blue-detuned driven), then the generated entanglement is transferred to the optical mode and microwave mode through the state transfer mechanism (red-detuned driven) between the microwave mode and phonon mode and is further transferred to the optical mode and magnon mode by the magnetic-dipole interaction between the microwave mode and magnon mode. Adopting the negative logarithm criterion, the variations of the optomicrowave and optomagnonic entanglements with detuning, coupling strength, and decay rate are thoroughly investigated. Furthermore, the optimal coherent feedback parameters and the physical mechanisms of generating and transferring entanglement are analyzed, and the entanglement enhancements by adding the feedback loop are discussed. The results show that after adding coherent feedback, optomicrowave entanglement and optomagnonic entanglement can be enhanced effectively within a wide range of parameters and the enhancement can also be well maintained. Our findings provide a theoretical basis for connecting different nodes (different physical systems) to construct hybrid quantum networks, flexibly controlling the quantum properties of magnons, and preparing macroscopic quantum states.
The preparation of highly entangled states involving multiparticle systems is of crucial importance in quantum physics, playing a fundamental role in exploring the nature of quantum mechanics and offering essential quantum resources for nascent quantum technologies that surpass classical limits. Here we present how to generate and manipulate a tripartite entangled state of photons, phonons, and magnons within a hybrid cavity magnomechanical system. It is shown that simultaneously applying two coherent driving fields to this system in opposite input directions enables a coherent and effective way to regulate the magnomechanical interaction by tuning the phase difference of the driving fields. Based on this feature, it is found that the tripartite entanglement also becomes phase dependent and can be enhanced for certain phase differences. More interestingly, it is shown that the robustness of tripartite entanglement against environmental thermal noises can also be improved by choosing a proper phase difference of the driving fields. Our findings offer a promising way to manipulate and protect fragile tripartite entanglement, which is applicable to a wide range of quantum protocols that require multipartite entangled resources such as quantum communication and quantum metrology.
Abstract Finding new strategies for the generation and preservation of quantum resources, e.g. entanglement between spatially separated macroscopic systems enables reliable and fertile platforms to study both fundamental quantum physics and fruitful applications such as quantum networks and distant quantum information processing. Here, we want to address how to generate magnon-magnon entanglement (MME) in an optomagnonic system based on the optical Bell-state measurement. To do so, we consider a hybrid optomagnonic system comprising of two identical, but distant dissipative microwave cavities, each containing a ferromagnetic YIG sphere and a superconducting qubit. Besides, each subsystem is driven via an external laser field. We numerically simulate the solution of the corresponding master equation and discuss the time-dependent as well as the steady state entanglement between the distant magnon modes at different interaction regime. Also, the fidelity of the generated entangled states is studied in detail. Generally, the dissipative environmental effects plague the MME, however, it is possible to generate a considerable amount of MME even at the steady state regime. Also, the results show that the robust MME may be enhanced by applying a relatively strong external pump decreasing the relative magnon damping rate as well as increasing the relative qubit-photon coupling strength, while some other parameters involved in the model, i.e. the atomic damping rate and detuning parameter do not considerably affect the amplitude (the maximum value) of MME. Exceptionally, although the magnon damping rate decreases the amount of MME, the entanglement stability takes place in a longer time interval in the strong magnonic damping regime. Moreover, the maximum of the steady state entanglement may be obtained in the moderate magnon-photon coupling regime provided that the system is driven by strong external pumps. Furthermore, the system can generate robust MME at steady state, especially in the small detuning regime. Our further investigations show that the system can provide relatively high-fidelity magnonic entangled states even in the presence of inevitable environmental effects. The proposed model offers an attractive platform for the generation of quantum resources to establish long-distance quantum networks based on magnonic and photonic systems.
Cavity optomagnomechanics provides a versatile platform to explore macroscopic quantum correlations, particularly nonreciprocal entanglement. In this work, we propose a theoretical scheme to generate switchable bipartite and tripartite entanglement in an optomagnomechanical ring cavity by exploiting phase-controlled magnon squeezing. Indeed, two spatially separated ferrimagnetic YIG microbridges become entangled through their magnetostriction-mediated coupling to mechanical motion and a common cavity field via radiation-pressure interaction. The squeezing process introduces two phase-dependent contributions to the magnon response, namely an effective detuning shift Δθj and a quadrature-damping contribution κθj, both of which reverse sign upon a π phase shift, providing an in situ control to switch the entanglement response. The nonreciprocal entanglement is defined operationally through the asymmetric entanglement response under the phase reversal θj→θj+π, quantified by normalized contrast ratios CE and CR, which measure the relative difference between the entanglement obtained at θj and at the phase-reversed configuration θj+π. The resulting phase-tuning method provides a flexible and robust route to achieve high-contrast bipartite and tripartite entanglement within stable parameter regions, establishing magnon squeezing as a practical quantum resource for switchable quantum correlations in hybrid platforms.