Enhanced Tripartite Interactions in Spin-Magnon-Mechanical Hybrid Systems

Magnetic-field-direction-controlled slow light and second-order sidebands in a cavity-magnon optomechanical system

We theoretically study how the magnetic field direction controls both the transmission rate and the group delay of the signal, as well as the second-order sideband process in a hybrid cavity-magnon optomechanical system. By tuning the direction of the bias magnetic field, either a positive or negative magnon Kerr coefficient can be achieved, leading to a corresponding shift in the magnon frequency. As a result, the transmission rate can be significantly modified, resulting in a Fano-like transparency spectrum governed by the magnetic field direction, along with a slow-to-fast light switch also influenced by that direction. Moreover, we study the impact of magnetic field direction on the second-order sidebands, revealing that the enhancement of the second-order sideband effect is dependent on this direction. These findings pave the way to engineering magnon Kerr nonlinearity-assisted optomechanical devices for applications in signal propagation and storage.

Magnon-Skyrmion Hybrid Quantum Systems: Tailoring Interactions via Magnons

Coherent and dissipative interactions between different quantum systems are essential for the construction of hybrid quantum systems and the investigation of novel quantum phenomena. Here, we propose and analyze a magnon-skyrmion hybrid quantum system, consisting of a micromagnet and nearby magnetic skyrmions. We predict a strong-coupling mechanism between the magnonic mode of the micromagnet and the quantized helicity degree of freedom of the skyrmion. We show that with this hybrid setup it is possible to induce magnon-mediated nonreciprocal interactions and responses between distant skyrmion qubits or between skyrmion qubits and other quantum systems like superconducting qubits. This work provides a quantum platform for the investigation of diverse quantum effects and quantum information processing with magnetic microstructures.

Long-distance transmission of arbitrary quantum states between spatially separated microwave cavities

Long-distance transmission between spatially separated microwave cavities is a crucial area of quantum information science and technology. In this work, we present a method for achieving long-distance transmission of arbitrary quantum states between two microwave cavities, by using a hybrid system that comprises two microwave cavities, two nitrogen-vacancy center ensembles (NV ensembles), two optical cavities, and an optical fiber. Each NV ensemble serves as a quantum transducer, dispersively coupling with a microwave cavity and an optical cavity, which enables the conversion of quantum states between a microwave cavity and an optical cavity. The optical fiber acts as a connector between the two optical cavities. Numerical simulations demonstrate that our method allows for the transfer of an arbitrary photonic qubit state between two spatially separated microwave cavities with high fidelity. Furthermore, the method exhibits robustness against environmental decay, parameter fluctuations, and additive white Gaussian noise. Our approach offers a promising way for achieving long-distance transmission of quantum states between two spatially separated microwave cavities, which may have practical applications in networked large-scale quantum information processing and quantum communication.