  Solid-state qubits with a photonic interface is very promising for quantum
networks. Color centers in silicon carbide have shown excellent optical and
spin coherence, even when integrated with membranes and nano-structures.
Additionally, nuclear spins coupled with electron spins can serve as long-lived
quantum memories. Pioneering work in previous has realized the initialization
of a single nuclear spin and demonstrated its entanglement with an electron
spin. In this paper, we report the first realization of single-shot readout for
a nuclear spin in SiC. We obtain a deterministic readout fidelity of 98.2% with
a measurement duration of 1.13 ms. With a dual-step readout scheme, we obtain a
readout fidelity as high as 99.5% with a success efficiency of 89.8%. Our work
complements the experimental toolbox of harnessing both electron and nuclear
spins in SiC for future quantum networks.
