Characterization of the nuclear spin environment in 4H-silicon carbide for single shot readout*

The V2 center in silicon carbide emerged as platform for CMOS compatible optically interfaced spin systems in the solid state. Recently, long coherence times and nearly transform limited photon emission were shown, even after integration into nanostructures. Furthermore, two weakly coupled nuclear spins were coherently controlled [1]. However, the V2 center inherits a strong phonon coupling to a metastable state manifold, leading to electron spin flip processes. This currently limits the readout fidelity. Our goal is to overcome this issue by implementation of a nuclear spin assisted single shot readout scheme [2].

Utilizing nuclear spins as quantum memories requires a detailed characterization of the nuclear spin environment. Here, we will present our recent accomplishments in the characterization of the nuclear spin environment via optically detected magnetic resonance (ODMR) and 5-pulse electron spin echo envelope modulation (ESEEM) sequences. The ESEEM sequence can be used to blind strongly coupled nuclear spins. This enables us to characterize weakly coupled nuclear spins even in the presence of strongly coupled nuclear spins. Finally, we compare the obtained coupling parameters with a theoretical model in order to select the optimal nuclear spin for the deterministic readout scheme.

[1] C. Babin et al., Nature Mat. 21, 67-73 (2022)

[2] P. Neumann et al., Science 329, 542-544 (2010)