Coherent spin dynamics of hyperfine-coupled vanadium impurities in silicon carbide

Spin-active optical defects in silicon carbide (SiC) are promising contenders for applications in quantum technology. The vanadium defect is of particular technological interest, as it combines emission at a telecom wavelength with a host material that is compatible with industrial semiconductor processing methods [1-2]. Compared to defects such as the NV center in diamond or the divacancy in SiC, its spin-orbit and hyperfine coupling are much stronger, but how this affects their spin coherence is little explored [3]. Here we show coherent spin dynamics of an ensemble of vanadium defects, of which a part is strongly coupled to neighboring nuclear spins and a part is isolated from it, around a clock transition. We find spin dephasing times up to 7.2 μs, and coherence times that can be extended well beyond tens of microseconds by applying a Hahn spin-echo . We demonstrate that strong coupling to neighboring nuclear spins does not compromise the coherence of the central vanadium spin. These findings indicate the potential of this system for use as a coherent spin register, and helps with understanding a wide class of defects with similar energy scales and crystal symmetries that are currently explored in diamond, silicon carbide, and hexagonal boron nitride.



[1] T. Astner et al., arXiv:2206.06240 (2022)

[2] G. Wolfowicz et al., Science Advances 6:eaaz1192 (2020)

[3] C. M. Gilardoni et al., New J. Phys. 23, 083010 (2021)