  We propose and analyze a novel realization of a solid-state quantum network,
where separated silicon-vacancy centers are coupled via the phonon modes of a
quasi-1D diamond waveguide. In our approach, quantum states encoded in
long-lived electronic spin states can be converted into propagating phonon
wavepackets and be reabsorbed efficiently by a distant defect center. Our
analysis shows that under realistic conditions, this approach enables the
implementation of high-fidelity, scalable quantum communication protocols
within chip-scale spin-qubit networks. Apart from quantum information
processing, this setup constitutes a novel waveguide QED platform, where
strong-coupling effects between solid-state defects and individual propagating
phonons can be explored at the quantum level.
