Nitrogen-vacancy (NV−) color centers in diamond were created by implantation of 7 keV N15(I=1∕2) ions into type IIa diamond. Optically detected magnetic resonance was employed to measure the hyperfine coupling of single NV− centers. The hyperfine spectrum from NV−15 arising from implanted N15 can be distinguished from NV−14 centers created by native N14(I=1) sites. Analysis indicates 1 in 40 implanted N15 atoms give rise to an optically observable NV−15 center. This report ultimately demonstrates a mechanism by which the yield of NV− center formation by nitrogen implantation can be measured.
Nitrogen-vacancy (NV−) color centers in diamond were created by implantation of 7 keV N15(I=1∕2) ions into type IIa diamond. Optically detected magnetic resonance was employed to measure the hyperfine coupling of single NV− centers. The hyperfine spectrum from NV−15 arising from implanted N15 can be distinguished from NV−14 centers created by native N14(I=1) sites. Analysis indicates 1 in 40 implanted N15 atoms give rise to an optically observable NV−15 center. This report ultimately demonstrates a mechanism by which the yield of NV− center formation by nitrogen implantation can be measured.
Nitrogen-vacancy defect color centers are created in a high purity single crystal diamond by nitrogen-ion implantation. Both optical spectrum and optically detected magnetic resonance are measured for these artificial quantum emitters. Moreover, with a suitable mask, a lattice composed of nitrogen-vacancy centers is fabricated. Rabi oscillation driven by micro-waves is carried out to show the quality of the ion implantation and potential in quantum manipulation. Along with compatible standard lithography, such an implantation technique shows high potential in future to make structures with nitrogen-vacancy centers for diamond photonics and integrated photonic quantum chip.
Abstract Nitrogen vacancy (NV) centers in diamond are a platform for several important quantum technologies, including sensing, communication and elementary quantum processors. In this letter we demonstrate the creation of NV centers by implantation using a deterministic single ion source. For this we sympathetically laser-cool single N 2 + 15 molecular ions in a Paul trap and extract them at an energy of 5.9 keV. Subsequently the ions are focused with a lateral resolution of 121(35) nm and are implanted into a diamond substrate without any spatial filtering by apertures or masks. After high-temperature annealing, we detect the NV centers in a confocal microscope and determine a conversion efficiency of about 0.6%. The 15NV centers are characterized by optically detected magnetic resonance on the hyperfine transition and coherence time.
Precise control over the spatial distribution and charge state of nitrogen-vacancy (NV) centers in diamond is a key requirement for further advancing this platform in quantum sensing and photonic applications. Here, we investigate nitrogen ion implantation as a scalable method to engineer NV centers in bulk single-crystalline (SC) and a 5 μ m -thick polycrystalline (PC) diamond membrane. Nitrogen-doped regions (1–80 ppm) were fabricated using a 0.7 MeV ion beam and high-temperature annealing, with NV center formation verified by confocal fluorescence imaging and spectral analysis. In SC bulk diamond, we estimate the NV concentration from spectral analysis and model the fluorescence response as a function of implantation dose, capturing both the initial increase at low concentrations and a saturation behavior at higher doses due to quenching mechanisms. In contrast, PC diamond membranes show a weaker dependence at low implantation fluences, consistent with pre-existing nitrogen impurities, thus making a statistical model significantly more complex. The activation yield is found to be of order of 1%, which is lower than in N-rich diamond samples, as implanted N is predominantly interstitial. Photoluminescence spectroscopy indicates that NV 0 is the dominant charge state in both materials, with a laser-power-dependent redistribution between neutral and negative charge states. Optically detected magnetic resonance (ODMR) measurements in SC bulk diamond resolve the hyperfine structure and allow extraction of the dephasing time ( T 2 ∗ ), while in PC diamond membranes, where NV centers tend do form near the grain boundaries, the ODMR signals are observed but spectral resolution is currently limited by impurities, grain-dependent NV orientations, and photoluminescence background.
The nitrogen-vacancy (NV) centers in diamond are amongst the most promising candidates for quantum information applications. Up to now the creation of such defects was highly probabilistic, requiring many copies of the nanodevice. Here we show that by employing a two step implantation process which includes low dose N2+ molecular ion implantations followed by high dose C implantation can increase the generation efficiency of NV centers by over 50%. Moreover, we detected intrinsic N14 concentration as low as 0.07 ppb by converting the nitrogen impurities into NV and then counting the single centers by using a confocal microscope.
Scalable realizations of quantum network technologies utilizing the nitrogen vacancy center in diamond require creation of optically coherent NV centers in close proximity to a surface for coupling to optical structures. We create single NV centers by 15N ion implantation and high-temperature vacuum annealing. Origin of the NV centers is established by optically detected magnetic resonance spectroscopy for nitrogen isotope identification. Near lifetime-limited optical linewidths (< 60 MHz) are observed for the majority of the normal-implant (7∘, ≈ 100 nm deep) 15NV centers. Long-term stability of the NV− charge state and emission frequency is demonstrated. The effect of NV-surface interaction is investigated by varying the implantation angle for a fixed ion-energy, and thus lattice damage profile. In contrast to the normal implant condition, NVs from an oblique-implant (85∘, ≈ 20 nm deep) exhibit substantially reduced optical coherence. Our results imply that the surface is a larger source of perturbation than implantation damage for shallow implanted NVs. This work supports the viability of ion implantation for formation of optically stable NV centers. However, careful surface preparation will be necessary for scalable defect engineering.
Nitrogen-vacancy (NV) centers are point defects in diamond formed by one substitutional nitrogen atom and an adjacent vacancy. Low spectral diffusion is a necessary property for NV centers to be qubit candidates. To characterize differences between naturally formed and ion implanted NV centers, diamond samples were studied that contained both types. The ion implantation process used 15N to be able to differentiate from the 14N naturally formed NV centers. This project focused on identifying the isotope of a single NV center, which is the first step toward understanding differences in their emissive properties. Code was developed to execute, and then automate, the three experiments necessary to identify the isotope of a single NV center: Continuous Wave Optically Detected Magnetic Resonance (CW ODMR), Rabi oscillations, and Pulsed ODMR. The code was implemented on a test sample, where it successfully identified the isotope of several NV centers. The next step in this project is to link the isotope of NV centers to their emissive properties, with a goal of producing reliable qubits for quantum information processing circuits.