  A distributed quantum network would require quantum nodes capable of
performing arbitrary quantum information protocols with high fidelity. So far
the challenge has been in realizing such quantum nodes with features for
scalable quantum computing. We show here that using the solid-state spins in
4H-Silicon Carbide (4H-SiC) such a goal could be realized, wherein a controlled
generation of highly coherent qubit registers using nuclear spins is possible.
Using a controlled isotope concentration and coherent control we perform here
atomistic modeling of the central spin system formed by the electron spin of a
silicon vacancy color center ($V_{Si}^-$-center) and the non-interacting
nuclear spins. From this we lay out conditions for realizing a scalable
nuclear-spin ($^{13}C$ or $^{29}Si$) register, wherein independent control of
the qubits alongside their mutual controlled operations using the central
electron spin associated to the $V_{Si}^-$-center in 4H-SiC are achieved.
Further, the decoherence and entanglement analysis provided here could be used
to evaluate the quantum volume of these nodes. Our results mark a clear route
towards realizing scalable quantum memory nodes for applications in distributed
quantum computing networks and further for quantum information protocols.
