Oxygen-vacancy origin of robust surface-proximity spin centers in silicon carbide
Year: 2026
Type: article
Abstract: Spin defects promise atomic-scale resolution and single-electron sensitivity, but typically deteriorate near surfaces. The PL5 and PL6 centers in SiC have emerged as a notable exception, exhibiting high optical contrast, long spin coherence times, and stable charge states within a few nanometers of the surface at room temperature. However, deterministic creation and scalable fabrication of these centers remain limited by their unresolved microscopic origins, with PL5 and PL6 frequently discussed in connection with divacancies and stacking faults. Here, we show that PL5 and PL6 do not originate from stacking faults, as regions with and without these planar defects exhibit comparable emitter densities. Instead, oxygen implantation increases the yield by more than an order of magnitude compared to nitrogen, and isotopic implantation with 17O yields a spin-5/2 hyperfine signature in the ODMR spectra, providing direct confirmation of oxygen involvement. From the characterization of the zero-field-splitting tensor and hyperfine interactions, together with ab initio calculations, we assign PL5 and PL6 to OCVSi defects in the kh and hh configurations, respectively. These results establish a basis for deterministic generation of near-surface spin qubits and their scalable integration for quantum photonics and nanoscale quantum sensing.
Source: The Innovation Physics
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7214068340