Electron spin decoherence in silicon carbide nuclear spin bath

Abstract

In this Rapid Communication, we study the electron spin decoherence of single defects in silicon carbide (SiC) nuclear spin bath. We find that, although the natural abundance of $^{29}\mathrm{Si}$ (${p}_{\mathrm{Si}}=4.7%$) is about four times larger than that of ${}^{13}\mathrm{C}$ (${p}_{\mathrm{C}}=1.1%$), the electron spin coherence time of defect centers in SiC nuclear spin bath in a strong magnetic field ($B>300\phantom{\rule{0.28em}{0ex}}\mathrm{G}$) is longer than that of nitrogen-vacancy (NV) centers in ${}^{13}\mathrm{C}$ nuclear spin bath in diamond. In addition to the smaller gyromagnetic ratio of $^{29}\mathrm{Si}$, and the larger bond length in SiC lattice, a crucial reason for this counterintuitive result is the suppression of the heteronuclear-spin flip-flop process in a finite magnetic field. Our results show that electron spin of defect centers in SiC are excellent candidates for solid state spin qubit in quantum information processing.