Microwave-optics entanglement via coupled opto- and magnomechanical microspheres

TL;DR

This paper proposes a novel hybrid system using coupled microspheres to generate stationary microwave-optics entanglement, advancing quantum network capabilities by bridging microwave and optical frequencies.

Contribution

It introduces a new mechanism utilizing coupled opto- and magnomechanical microspheres to efficiently produce microwave-optics entanglement with current technology.

Findings

Stationary entanglement between magnon and optical modes achieved.

Mechanism leverages simultaneous magnomechanical and optomechanical scattering.

Potential for integration into hybrid quantum networks.

Abstract

Microwave-optics entanglement plays a crucial role in building hybrid quantum networks with quantum nodes working in the microwave and optical frequency bands. However, there are limited efficient ways to produce such entanglement due to the large frequency mismatch between the two regimes. Here, we present a new mechanism to prepare microwave-optics entanglement based on a hybrid system of two coupled opto- and magnomechanical microspheres, i.e., a YIG sphere and a silica sphere. The YIG sphere holds a magnon mode and a vibration mode induced by magnetostriction, while the silica sphere supports an optical whispering-gallery mode and a mechanical mode coupled via an optomechanical interaction. The two mechanical modes are close in frequency and directly coupled via physical contact of the two microspheres. We show that by simultaneously activating the magnomechanical (optomechanical) Stokes (anti-Stokes) scattering, stationary entanglement can be established between the magnon and optical modes via mechanics-mechanics coupling. This leads to stationary microwave-optics entanglement by further coupling the YIG sphere to a microwave cavity and utilizing the magnon-microwave state swapping. Our protocol is within reach of current technology and may become a promising new approach for preparing microwave-optics entanglement, which finds unique applications in hybrid quantum networks and quantum information processing with hybrid quantum systems.