Dynamical phase-field model of cavity electromagnonic systems

Abstract Cavity electromagnonic system, which simultaneously consists of cavities for microwave photons, magnons (quanta of spin waves), and acoustic phonons, provides an exciting platform to achieve coherent energy transduction among different physical systems down to single quantum level. Here we report a dynamical phase-field model that allows simulating the coupled dynamics of the electromagnetic waves, magnetization, and strain in 3D electromagnonic systems which have previously not been considered together. As examples of application, we computationally demonstrate the excitation of hybrid magnon-photon modes (magnon polaritons), Floquet-induced magnonic Aulter-Townes splitting, dynamical energy exchange (Rabi oscillation) and relative phase control (Ramsey interference) between the two magnon polariton modes. The simulation results are well consistent with analytical calculations based on Floquet Hamiltonian theory. With the capability to predict coupling strength, dissipation rates, and temporal evolution of photon/magnon/phonon mode profiles using only fundamental materials parameters as inputs, the present dynamical phase-field model represents a critically needed computational tool to guide and accelerate the fabrication of the cavity electromagnonic system and the design of operating conditions for applications in quantum sensing, transduction, and communication.