Generation of Bell and Greenberger-Horne-Zeilinger states from a hybrid qubit-photon-magnon system

Abstract

We propose a level-resolved protocol in a hybrid architecture for connecting a superconducting qubit and a magnon mode contained within a microwave cavity (resonator) to generate local and global entangled states, enabling a wide range of applications in quantum communication, quantum metrology, and quantum information processing. Exploiting the high-degree controllability in such a hybrid qubit-photon-magnon system, we derive the effective Hamiltonians at the second-order resonant points by virtue of the strong general Rabi interactions between the resonator and the qubit and between the resonator and the magnon. Consequently, we can efficiently generate the Bell states of the photon-magnon and the qubit-magnon subsystems and the Greenberger-Horne-Zeilinger state of the whole hybrid system. The robustness of our protocol is checked against a nonvanishing tuning time of system frequency and the environmental noise by the Lindblad master equation. Our work makes this hybrid platform of high-degree controllability a high-fidelity candidate for preparing the multiple maximally entangled states.