Abstract Hybridized magnonic–photonic systems promise novel applications for future information processing technologies. Here, a hybrid magnonic system comprising of a qutrit (Λ‐type three‐level atom) and a ferromagnetic YIG sphere is considered. Indeed, the whole system is driven by two light fields under the influence of the thermal environment. The indirect magnon–atom interaction is established via the virtual photon exchange. The associated Lindblad master equation is derived and its solution is found to investigate the nonclassical feature, especially in the steady‐state solution. Generally, the system shows considerable nonclassicality, that is, strong magnon antibunching and magnon blockade. In fact, the feasibility of using such a hybrid system to prepare a single‐magnon source based on magnon blockade effects we theoretically demonstrated. Besides, the considered system may be exploited to generate robust and stable magnon–atom entanglement. The appearance of magnon blockade and magnon–atom entanglement in the Λ‐type atom may have its origin in the fact that the atom is trapped in different superposition states, induced by the quantum interference phenomenon. The proposed model and the corresponding results may open up an intriguing prospect to prepare a single‐magnon source and provide further benefits through concatenating with photons in optomagnonic systems.
Abstract Hybridized magnonic–photonic systems promise novel applications for future information processing technologies. Here, a hybrid magnonic system comprising of a qutrit (Λ‐type three‐level atom) and a ferromagnetic YIG sphere is considered. Indeed, the whole system is driven by two light fields under the influence of the thermal environment. The indirect magnon–atom interaction is established via the virtual photon exchange. The associated Lindblad master equation is derived and its solution is found to investigate the nonclassical feature, especially in the steady‐state solution. Generally, the system shows considerable nonclassicality, that is, strong magnon antibunching and magnon blockade. In fact, the feasibility of using such a hybrid system to prepare a single‐magnon source based on magnon blockade effects we theoretically demonstrated. Besides, the considered system may be exploited to generate robust and stable magnon–atom entanglement. The appearance of magnon blockade and magnon–atom entanglement in the Λ‐type atom may have its origin in the fact that the atom is trapped in different superposition states, induced by the quantum interference phenomenon. The proposed model and the corresponding results may open up an intriguing prospect to prepare a single‐magnon source and provide further benefits through concatenating with photons in optomagnonic systems.
In this paper, we propose a quantum interference mediated control of switching between magnon-atom entanglement and magnon blockade. A three-level $\mathrm{\ensuremath{\Lambda}}$ configuration atomic ensemble and a yttrium iron garnet sphere are simultaneously coupled to a microwave cavity mode through magnetic dipole interaction. By applying two strong fields to drive the atoms, the resonant coupling between a dressed-state atomic transition and the magnon mode, without direct interaction, is established by adiabatically eliminating the cavity field. Interestingly, the anti-Jaynes-Cummings (JC) interaction and the JC interaction are alternatively formed when the atoms are trapped into different superposition states induced by quantum interference, causing the appearance of hybrid magnon-atom entanglement and magnon quantum blockade, respectively. The coherent-controlled hybrid magnon-atom entanglement and magnon blockade may find potential applications in quantum information processing.
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.
ABSTRACT We propose a scheme to realize magnon blockade in a hybrid system composed of a transmon‐type superconducting qubit directly coupled to the magnon mode of a single‐crystalline yttrium‐iron‐garnet sphere. By applying two‐tone driving to the qubit, we engineer an effective Hamiltonian for the magnon mode including both single‐magnon and two‐magnon interaction. Due to the destructive interference between two transition paths, the two‐magnon excitation is suppressed, and thus the unconventional magnon blockade can be achieved. We also demonstrate that the intrinsic anharmonicity of the qubit can be transferred to the magnon mode through their coherent hybridization, but this anharmonicity has almost no influence on the blockade effect. Through solving the second‐order correlation function analytically and numerically, we show that the scheme can be realized under experimentally feasible conditions and remains robust against system dissipations and environment temperature. Therefore, the presented work provides a viable path toward generating single‐magnon sources and advancing quantum information processing with magnonic platforms.
Abstract Magnon and photon blockade implementation and manipulation have significant practical applications in quantum information processing and quantum metrology due to their tight relations to single-photon and -magnon source devices. In this paper, we propose an experimentally feasible hybrid scheme for the dynamical description of the tripartite interacting system consisting of magnon and phonon modes with photons in an optomechanical system, from which we aim to explore the quantum statistics, as well as the magnon and photon blockade phenomenon. To achieve the purpose, the dissipative solution of the system is obtained with the help of the Lindblad master equation. Via employing the equal-time second-order correlation function and using the steady state solution of the system, the statistics and blockade effects of magnon and photon are analyzed and also their dependence on the parameters involved in the system are discussed. Utilizing feasible parameters, our simulations illustrate that, sub-Poissonian behavior and therefore, blockade of magnon and photon are simultaneously achieved. More importantly, the mentioned blockade effects can be obtained in a range of parameters (and not with specific) which makes our proposal easy to access, experimentally. Considering the above realizations, the introduced scheme opens up a pathway to design single-magnon and -photon generators, which are of crucial importance in advanced quantum science and technologies.
Abstract Magnon blockade (MB) is a fundamental quantum phenomenon for generating single-magnon states, and has gradually become one of the candidates for quantum information processing. We extend existing blockade optimization schemes to a hybrid system consisting of a YIG micromagnet and a skyrmion, and propose a theoretical scheme for achieving MB on this platform. Under weak magnon probing and external driving of the skyrmion qubit, the second-order correlation function is analytically derived, and the optimal parameter conditions for both conventional and unconventional MB are identified. By appropriately adjusting the intensities of the driving and probing fields, the MB effect is significantly enhanced, multi-magnon excitations are effectively suppressed, and strong antibunching is achieved. Further analysis reveals that MB originates from two distinct physical mechanisms: conventional blockade induced by anharmonicity of the energy level structure, and unconventional blockade arising from quantum interference between different transition paths. On this platform, the two mechanisms coexist and can be synergistically controlled, and their cooperation yields a blockade effect superior to that of either mechanism alone. This work thus provides a feasible theoretical scheme for the effective manipulation of MB effects.
We propose a feasible experimental model to investigate the generation and characterization of nonclassical states in a cavity optomagnonic system consisting of a ferromagnetic YIG sphere that simultaneously supports both the magnon mode and two whispering gallery modes of optical photons. The photons undergo the magnon-induced Brillouin light scattering, which is a well-established tool for the cavity-assisted manipulations of magnons as well as magnon spintronics. At first, we derive the desired interaction Hamiltonian under the influence of the anti-Stokes scattering process and then proceed to analyze the dynamical evolution of quantum statistics of photons and magnons as well as their intermodal entanglement. The results show that both photons and magnons generally acquire some nonclassical features, e.g., the strong antibunching and anti-correlation. Interestingly, the system may experience the perfect photon and magnon blockade phenomena, simultaneously. Besides, the nonclassical features may be protected against the unwanted environmental effects for a relatively long time, especially, in the weak driving field regime and when the system is initiated with a small number of particles. However, it should be noted that some fast quantum-classical transitions may occur in-between. Although the unwanted dissipative effects plague the nonclassical features, we show that this system can be adopted to prepare optomagnonic entangled states. The generation of entangled states depends on the initial state of the system and the interaction regime. The intermodal photon-magnon entanglement may be generated and pronounced, especially, if the system is initialized with low intensity even Schrödinger cat state in the strong coupling regime. The cavity-assisted manipulation of magnons is a unique and flexible mechanism that allows an interesting test bed for investigating the interdisciplinary contexts involving quantum optics and spintronics. Moreover, such a hybrid optomagnonic system may be used to design both on-demand single-photon and single-magnon sources and may find potential applications in quantum information processing.