We demonstrate that silicon carbide (SiC) with natural isotope abundance can preserve a coherent spin superposition in silicon vacancies over unexpectedly long time approaching 0.1 seconds. The spin-locked subspace with drastically reduced decoherence rate is attained through the suppression of heteronuclear spin cross-talking by applying a moderate magnetic field in combination with dynamic decoupling from the nuclear spin baths. We identify several phonon-assisted mechanisms of spin-lattice relaxation, ultimately limiting quantum coherence, and find that it can be extremely long at cryogenic temperature, equal or even longer than 8 seconds. Our approach may be extended to other polyatomic compounds and open a path towards improved qubit memory for wafer-scale quantum techmologies.
@article{arxiv.1602.05775,
title = {Locking of electron spin coherence over fifty milliseconds in natural silicon carbide},
author = {D. Simin and H. Kraus and A. Sperlich and T. Ohshima and G. V. Astakhov and V. Dyakonov},
journal= {arXiv preprint arXiv:1602.05775},
year = {2017}
}
Comments
Added extended data analysis based on quantum process tomography, discussion of spin-lattice relaxation mechanisms