ABSTRACT Recently, magnomechanical systems have emerged as promising platforms for quantum technologies, exploiting magnon–photon–phonon interactions to store high‐fidelity quantum information. In this paper, we propose a novel scheme to entangle two spatially separated ferrimagnetic YIG crystals by injecting a laser field into an optomagnonic ring cavity. The proposed optomagnomechanical configuration utilizes the coupling between magnetostriction‐induced mechanical displacements and the optical cavity via radiation pressure. Magnons, collective spin excitations in macroscopic ferrimagnets, are directly driven by an electromagnetic field. We demonstrate the generation of a robust macroscopic entangled state via exciting the optical cavity with a red‐detuned laser field and the YIG crystals with blue‐detuned microwave fields. Our analysis reveals that magnon entanglement vanishes for identical magnomechanical couplings and remains robust against thermal fluctuations. Moreover, the quantum steering can be tuned directionally by the asymmetry of the magnomechanical coupling, allowing for a selective control of the optomagnetic quantum correlations. The entangled magnon modes in two ferrimagnetic crystals represent genuine macroscopic quantum states with potential applications in the study of macroscopic quantum mechanics and quantum information processing based on magnonics. Our model is based on experimentally accessible parameters, providing a feasible route to quantum technologies.
ABSTRACT Recently, magnomechanical systems have emerged as promising platforms for quantum technologies, exploiting magnon–photon–phonon interactions to store high‐fidelity quantum information. In this paper, we propose a novel scheme to entangle two spatially separated ferrimagnetic YIG crystals by injecting a laser field into an optomagnonic ring cavity. The proposed optomagnomechanical configuration utilizes the coupling between magnetostriction‐induced mechanical displacements and the optical cavity via radiation pressure. Magnons, collective spin excitations in macroscopic ferrimagnets, are directly driven by an electromagnetic field. We demonstrate the generation of a robust macroscopic entangled state via exciting the optical cavity with a red‐detuned laser field and the YIG crystals with blue‐detuned microwave fields. Our analysis reveals that magnon entanglement vanishes for identical magnomechanical couplings and remains robust against thermal fluctuations. Moreover, the quantum steering can be tuned directionally by the asymmetry of the magnomechanical coupling, allowing for a selective control of the optomagnetic quantum correlations. The entangled magnon modes in two ferrimagnetic crystals represent genuine macroscopic quantum states with potential applications in the study of macroscopic quantum mechanics and quantum information processing based on magnonics. Our model is based on experimentally accessible parameters, providing a feasible route to quantum technologies.
We show how to prepare macroscopic entanglement between an atomic ensemble and a large number of magnons in a ferrimagnetic yttrium-iron-garnet crystal. Specifically, we adopt an optomagnomechanical configuration where the magnetostriction-induced magnomechanical displacement couples to an optical cavity via radiation pressure, and the latter further couples to an ensemble of two-level atoms that are placed inside the cavity. We show that, by properly driving the cavity and magnon modes, optomechanical entanglement is created which is further distributed to the atomic and magnonic systems, yielding stationary entanglement between atoms and magnons. The atom-magnon entanglement is a result of the combined effect of opto- and magnomechanical cooling and optomechanical parametric down-conversion interactions. A competition mechanism between two mechanical cooling channels is revealed. We further show that genuine tripartite entanglement of three massive subsystems, i.e., atoms, magnons, and phonons, can also be achieved in the same system. Our results indicate that the hybrid optomagnomechanical system may become a promising system for preparing macroscopic quantum states involving magnons, photons, phonons, and atoms.
Abstract We show how to prepare a steady-state entangled state between magnons and optical photons in an opto-magnomechanical configuration, where a mechanical vibration mode couples to a magnon mode in a ferrimagnet by the dispersive magnetostrictive interaction, and to an optical cavity by the radiation pressure. We find that, by appropriately driving the magnon mode and the cavity to simultaneously activate the magnomechanical Stokes and the optomechanical anti-Stokes scattering, a stationary optomagnonic entangled state can be created. We further show that, by activating the magnomechanical state–swap interaction and subsequently sending a weak red-detuned optical pulse to drive the cavity, the magnonic state can be read out in the cavity output field of the pulse via the mechanical transduction. The demonstrated entanglement and state-readout protocols in such a novel opto-magnomechanical configuration allow us to optically control, prepare, and read out quantum states of collective spin excitations in solids, and provide promising opportunities for the study of quantum magnonics, macroscopic quantum states, and magnonic quantum information processing.
Abstract We present a scheme to entangle two magnon modes in a cavity magnomechanical system. The two magnon modes are embodied by collective motions of a large number of spins in two macroscopic ferrimagnets, and couple to a single microwave cavity mode via magnetic dipole interaction. We show that by activating the nonlinear magnetostrictive interaction in one ferrimagnet, realized by driving the magnon mode with a strong red-detuned microwave field, the two magnon modes can be prepared in an entangled state. The entanglement is achieved by exploiting the nonlinear magnon-phonon coupling and the linear magnon-cavity coupling, and is in the steady state and robust against temperature. The entangled magnon modes in two massive ferrimagnets represent genuinely macroscopic quantum states, and may find applications in the study of macroscopic quantum mechanics and quantum information processing based on magnonics.
ABSTRACT Combining radiation pressure and magnetostriction interactions offers a powerful opportunity to engineer tunable cavity optomagnomechanics, enabling rich physical phenomena and promising quantum applications. We propose an electro–opto–magnomechanical system that combines radiation‐pressure, magnetostrictive and Coulomb interactions within a single device. The system comprises optical photons, magnons, and two spatially separated charged mechanical resonators coupled via a tunable Coulomb interaction. While, a coherent feedback loop enhances the generated quantum correlations. This hybrid configuration enables strong macroscopic quantum correlations among photons, magnons, and phonons, yielding robust magnon–phonon entanglement that persists up to 3.4 K for the first mechanical mode and 1.6 K for the second. The Coulomb interaction is used to control quantum steering, enabling one‐way and two‐way steering between magnon and phonon modes. Under experimentally feasible parameters, our results predict a teleportation fidelity of which exceeds the classical threshold, demonstrating suitability for continuous‐variable quantum communication. Our results establish a powerful framework toward magnon‐based quantum information processing and advanced quantum technologies.
Abstract It is showed how to generate and control the one‐way optomechanical steering in an optomagnomechanical system. In the scheme, the magnetostriction‐induced deformation displacement of a ferrimagnet couples to an optical cavity by radiation‐pressure interaction. The optical cavity resonates with the Stokes sideband of the laser drive field, leading to the optomechanical parametric down‐conversion interaction. The magnon mode resonates with the anti‐Stokes sideband of the microwave drive field, thereby cooling the mechanical motion. By adjusting the detuning between the magnon mode and the microwave drive field, we show the relative steady‐state population numbers of photons and phonons will be changed, therefore, the direction of the optomechanical steering can be controlled. The control of the quantum steering in this scheme does not require the introduction of additional dissipation and damping of the entangled parties, which means the one‐way steering can be generated with low mechanical damping, and has strong robustness against thermal noise. This finding may provide a novel platform to generate and control quantum steering in hybrid quantum system.
Abstract Microwave‐optics entanglement is a vital component for building hybrid quantum networks. Here, a new mechanism for preparing stationary entanglement between microwave and optical cavity fields in a cavity optomagnomechanical system is proposed. It consists of a magnon mode in a ferrimagnetic crystal that couples directly to a microwave cavity mode via the magnetic dipole interaction and indirectly to an optical cavity through the deformation displacement of the crystal. The mechanical displacement is induced by the magnetostrictive force and coupled to the optical cavity via radiation pressure. Both the opto‐ and magnomechanical couplings are dispersive. Magnon–phonon entanglement is created via magnomechanical parametric down‐conversion, which is further distributed to optical and microwave photons via simultaneous optomechanical beamsplitter interaction and electromagnonic state‐swap interaction, yielding stationary microwave‐optics entanglement. The microwave‐optics entanglement is robust against thermal noise, which will find broad potential applications in quantum networks and quantum information processing with hybrid quantum systems.