Spin polarization and temperature dependent lifetime of Vanadium qubits in SiC

Optically active solid-state spin defects have drawn great interest for their potential applications in quantum information science. In particular, vanadium (V⁴⁺) dopants in silicon carbide (SiC) have recently emerged as a promising platform for quantum communication due to its favorable characteristics including bright emission in the telecom O-band (1278 – 1388 nm) and an optically addressable electron-nuclear spin system within a commercially mature electronic platform. As a novel defect system, there remain important open questions regarding the fundamental properties of these qubit systems for quantum applications. Here, we further characterize the optical and spin properties of V⁴⁺ defects at different sites in 4H- and 6H-SiC at temperatures below 4K. We demonstrate all-optical spin polarization and readout, which we use to probe the spin lifetimes and its temperature dependence. Our results suggest that V⁴⁺ in SiC is a promising candidate for applications in quantum communication and networks.