Study On The Quantum Correlations Of Magnon Controlled By Photon And Atom

In the last few decades,with the boom in quantum technology,computing and detection capabilities have increased dramatically.In particular,the hybrid quantum systems,composed of distinct physical components with complementary functionalities,possess multitasking capabilities and thus may be better suited than others for specific tasks.Recently,the hybrid quantum system based on magnon has become a popular research direction.Magnon,the quanta of the collective excitation of magnetic materials,exhibits unique features and advantages,which lie in the high-spin density,low dissipation rate and large frequency tunability,as well as an excellent ability to coherently interact with other systems,including microwave photons,optical photons,phonons and superconducting qubits.A variety of interesting phenomena have been explored in hybrid system based on magnons,such as the generation of nonclassical states,magnon blockade,quantum entanglement,bistability and so on.On the other hand,as an important topic in quantum optics and laser physics,atomic coherence has always been one of the hot spots in scientific research.These phenomena,such as coherent population trapping,electromagnetically induced transparency and Raman effect,are of great application value to the research of fundamental physics and the development of quantum technology.Due to its unique properties and fundamental role in quantum theory,the quantum correlation effect has become an crucial resource of quantum technology and has important applications in quantum computing and quantum information processing.It is noteworthy that in the study of light and matter interactions,atomic coherence has proved to be an effective way to control quantum correlations.The topic of this paper is to realize the Coherently regulated quantum correlation effect based on magnons via the coherence effect induced by light and atoms.The innovative work includes the following three aspects:Firstly,we present a scheme to generate coherent coupling between the magnons and the superconducting artificial atom mediated by the dispersive cavities,and realize the entanglement between the two magnons via the quantum dissipation process induced by atomic coherence.In this system,the V-type superconducting atom located at the intersection of the cross-shaped cavity,and couples to two microwave cavity modes simultaneously.At the same time,a YIG(Y3Fe5O12 YIG)sphere is placed in each cavity,respectively.The atom can be dressed by the interaction of two dressing fields.After adjusting the frequency of the magnon resonant with the Rabi sidebands of the dressed atom and far-detuned from the microwave cavity fields,the effective coupling between the magnon and the dressed atom is realized via exchanging virtual photons in the dispersive cavities.By probing into the induced magnon-atom interaction,we reveal the two-channel dissipation mechanism of the artificial atomic reservoir,and we can obtain nearly ideal two-mode squeezing and entanglement of the two magnons for specific conditions.The quantum entanglement of the magnon modes in two massive ferrimagnets survives at the steady state and represents genuinely macroscopic quantum state,which may finds broad applications in the investigation of macroscopic quantum effects and the preparation of quantum devices.Secondly,we propose a scheme to generate remote asymmetric Einstein-PodolskyRosen(EPR)steering of two magnon modes via a single pathway of Bogoliubov dissipation.In this scheme,a Δ-type superconducting artificial atom coupled to two cavity modes and driven by a classical dressing field is considered.Simultaneously,the two microwave cavity fields are coupled to a magnon,respectively.The magnon and the dressed atoms are coherently coupled mediated by the dispersive cavities,and the magnon exhibits asymmetric steering characteristics due to the atomic coherent effect.Through the Bogoliubov transformation,we find that there are two ways of interaction between the atom and magnon Bogoliubov modes under different parameters.In each case,only one of the two Bogoliubov modes is coupled with the atom,and the other one is decoupled.After adiabatically eliminating the atom,when the coupled Bogoliubov mode is cooled by the artificial atom,the corresponding magnon mode can be steered by the other one,but not vice versa.We find that the steering directivity is determined by cooling either Bogoliubov mode selectively.Different from the conventional schemes,the asymmetric EPR steering does not require the asymmetry noise from the external environment but utilizes the asymmetry of intrinsic mechanism.In addition,The obtained asymmetric quantum correlations by one-channel Bogoliubov dissipation are immune to environmental decoherence,and do not require the initial preparation of nonclassical states.Finally,The direction of one-way magnon steering can be easily controlled due to the flexible mouldability of the magnons and the superconducting artificial atom.Finally,we generate magnon-atom-optical photon tripartite entanglement via the microwave photon-mediated Raman interaction.In our scheme,magnons in a macroscopic ferromagnet and optical photons in a cavity are induced into a Raman interaction with an atomic spin ensemble when a microwave field couples the magnons to one Raman wing.The controllable magnon-atom entanglement,magnon-optical photon entanglement,and even genuine magnon-atom-optical photon tripartite entanglements can be generated simultaneously via additional control fields.In addition,these bipartite and tripartite entanglements are robust against the environment temperature and decoherence.It’s worth noting that the magnons with inbuilt merits are good candidates for scalable quantum computation,the atomic ensemble is an ideal node for storing local quantum information,and the optical photons are robust long-distance quantum bus.Therefore,this quantum interface bridging the magnons,the atomic ensemble,and the optical photons,may provide a promising building block for hybrid quantum network.