Generation of entanglement and quantum steering via Josephson parametric amplifier in a dual cavity-magnon system

Abstract

In the two microwave (MW) cross-shaped cavity magnon system, we describe a method to produce multipartite entanglement and quantum steering. To achieve squeezed states of the magnons, a Josephson parametric amplifier (JPA) creates a squeezed vacuum field that drives the two cavities. We theoretically demonstrate that the cavity-cavity entanglement can be generated at the resonance point, however, increasing the cavity and magnon decay rates generate the cavity-magnon entanglement. By changing the squeezing parameter and increasing the decay rates, we can transfer the cavity-cavity entanglement to cavity-magnon entanglement. Furthermore, the cavity-cavity entanglement (survive up to 2.8K) was not only found to be much stronger but also more robust as compared to cavity-magnon entanglement (survive up to 0.4K). More importantly, the genuine photon-magnon-photon tripartite entanglement could be achieved, which is robust against thermal fluctuations and depends strongly on the squeezing parameter. Furthermore, for the current dual cavity-magnon system, two-way quantum steering is found when the optomagnonical couplings are equal. The current study offers a straightforward and practical method for achieving multipartite quantum correlations.