Generation of Bell and GHZ states from a hybrid qubit-photon-magnon system

TL;DR

This paper presents a protocol for generating entangled Bell and GHZ states in a hybrid qubit-photon-magnon system, demonstrating high controllability and robustness for quantum information applications.

Contribution

It introduces a level-resolved method to produce entangled states in a hybrid system using effective Hamiltonians at specific resonant points, advancing quantum state engineering.

Findings

Efficient generation of Bell states in photon-magnon and qubit-magnon subsystems.

Successful creation of GHZ state in the hybrid system.

Protocol robustness verified against environmental noise.

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 the local and global entangled states, enabling a wide range of applications in quantum communication, quantum metrology, and quantum information processing. Exploiting the high-degree of controllability in such a hybrid qubit-photon-magnon system, we derive effective Hamiltonians at the second- or the third-order resonant points by virtue of the strong counter-rotating 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. We also check the robustness of our protocol against the environmental noise by the Lindblad master equation. Our work makes this hybrid platform of high-degree of controllability a high-fidelity candidate for the realization of the maximally-entangled multiple states.