Photoluminescence from NV− centres in 5 nm detonation nanodiamonds: Identification and high sensitivity to magnetic field

This is the final version. Available from the publisher via the DOI in this record.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.Engineering and Physical Sciences Research Council (EPSRC

Nitrogen impurities and fluorescent nitrogen-vacancy centers in detonation nanodiamonds: identification and distinct features

This is the author accepted manuscript. The final version is available from Optical Society of America via the DOI in this recordWe show that nitrogen is the main impurity contained in detonation nanodiamonds at a concentration of 16,000 ppm. The content of nitrogen-vacancy NV− centers in these nanodiamonds is about 2.7 ppm, which is the largest of all known types of nanodiamonds of size less than 10 nm with artificially created NV− centers. The removal of graphite-like fragments from the nanodiamond surface allowed us to detect the characteristic photoluminescence of the NV− color centers in individual nanodiamond aggregates of sizes from 50–100 to 500–700 nm. We have further confirmed the detection of the negatively charged NV− through the observation of a strong decrease in the photoluminescence intensity when an external magnetic field is applied. Such an effect results from the optically detectable magnetic resonance of the electronic spin triplet ground state of NV− that cannot be observed in other emitting defects in a similar spectral range, including the neutral NV0 centers

Coherent Manipulation with Resonant Excitation and Single Emitter Creation of Nitrogen Vacancy Centers in 4H Silicon Carbide.

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