RESUMO
Silicon carbide (SiC) has become a key player in the realization of scalable quantum technologies due to its ability to host optically addressable spin qubits and wafer-size samples. Here, we have demonstrated optically detected magnetic resonance (ODMR) with resonant excitation and clearly identified the ground state energy levels of the NV centers in 4H-SiC. Coherent manipulation of NV centers in SiC has been achieved with Rabi and Ramsey oscillations. Finally, we show the successful generation and characterization of single nitrogen vacancy (NV) center in SiC employing ion implantation. Our results highligh the key role of NV centers in SiC as a potential candidate for quantum information processing.
RESUMO
The content of nitrogen-vacancy (NV-) colour centres in the nanodiamonds (DNDs) produced during the detonation of nitrogen-containing explosives was found to be 1.1 ± 0.3 ppm. This value is impressive for nanodiamonds of size < 10 nm with intentionally created NV- centres. The concentration was estimated from the electron paramagnetic resonance as determined from the integrated intensity of the g = 4.27 line. This line is related with "forbidden" ∆ms = 2 transitions between the Zeeman levels of a NV- centre's ground triplet state. Confocal fluorescence microscopy enables detection of the red photoluminescence (PL) of the NV- colour centres in nanoscale DND aggregates formed from the 5-nm nanoparticles. Subwavelength emitters consisting of NV- with sizes a few times smaller than the diffraction-limited spot are clearly distinguished. We have further observed an abrupt drop in the PL intensity when mixing and anti-crossing of the ground and excited states spin levels in NV- occurs under an applied external magnetic field. This effect is a unique quantum feature of NV- centres, which cannot be observed for other visible domain light-emitting colour centres in a diamond lattice.