Remote Entanglement of Solid-State Spin Qubits Integrated in Broadband Waveguides
arXiv:2607.12002
The paper demonstrates heralded remote entanglement between diamond tin‑vacancy spin qubits that are integrated into separate broadband on‑chip waveguides, using efficient photon emission and real‑time feedforward to generate a consistent entangled state.
Abstract
Solid-state spin-photon interfaces promise to scale quantum networks through on-chip photonic integration and multiplexed entanglement generation. To date, remote entanglement between integrated emitters has been realized only in cavity-enhanced systems, where fabrication yield and spectral matching remain major obstacles. Here we demonstrate heralded remote entanglement between diamond tin-vacancy spin qubits embedded in separate on-chip waveguides. Combining intrinsically efficient photon emission with a broadband waveguide architecture provides high device yield and obviates the need for spectral matching to cavity modes. We realize coherent optical and spin control and achieve high-visibility two-photon interference. By combining photon-mediated entanglement generation with real-time feedforward, we produce a consistent entangled state independent of the heralding pattern. These results establish waveguide-integrated tin-vacancy centers as a compelling platform for scalable quantum network nodes.