Hybrid spin-phonon architecture for scalable solid-state quantum nodes

Solid-state spins are promising for quantum information processing and networks, but their inhomogeneity hinders scalable control and entanglement. We propose a hybrid spin-phonon architecture based on spin-embedded SiC optomechanical crystal (OMC) cavities, which integrate photonic and phononic channels for multi-spin interactions. Using a Raman-facilitated process, spins strongly couple to the OMC cavity’s zero-point motion at 0.57 MHz, enabling coherent spin-phonon interactions. This interface supports a two-qubit controlled-Z gate with simulated fidelity of 96.80% and efficiently generates entangled Dicke states with over 99% fidelity by leveraging a robust spin-phonon dark state resilient to spectral inhomogeneity and excited-state loss. The platform offers potential scalability and all-to-all connectivity via phonons, along with optical links, enabling both entanglement generation and quantum acoustics studies in the solid state.