On the basis of the first-principles method, this paper discusses a new type of diamond PrV color center by using Vienna Ab-initio Simulation Package software and optimizes the possible configurations of the PrV defect. Theoretically, a stable structure of the diamond PrV color center is one where Pr is located at the center of the double vacancy. The electronic structure of the diamond color center is calculated by using this stable structure, and its energy band and energy level structures are obtained. A zero-phonon line (ZPL) of 1.0185 eV and emission wavelength of 1217.5 nm are predicted for the PrV color center. Calculation of the effects of co-doping of the diamond PrV color center with N or B atoms reveals improvements in energy band and energy level structures and provides a theoretical basis for the experimental preparation of PrV color centers.
On the basis of the first-principles method, this paper discusses a new type of diamond PrV color center by using Vienna Ab-initio Simulation Package software and optimizes the possible configurations of the PrV defect. Theoretically, a stable structure of the diamond PrV color center is one where Pr is located at the center of the double vacancy. The electronic structure of the diamond color center is calculated by using this stable structure, and its energy band and energy level structures are obtained. A zero-phonon line (ZPL) of 1.0185 eV and emission wavelength of 1217.5 nm are predicted for the PrV color center. Calculation of the effects of co-doping of the diamond PrV color center with N or B atoms reveals improvements in energy band and energy level structures and provides a theoretical basis for the experimental preparation of PrV color centers.
Abstract This study conducts a theoretical analysis on the stable structure, charge transfer, energy level transition, and electronic structure of a diamond yttrium vacancy color center. The color center in a diamond is very important as a single photon source material for quantum information processing technology and applications, such as temperature sensors, solid-state quantum systems, photonics, lighting, imaging technology, and biomedicine. Nanodiamond yttrium vacancy color centers are prepared using the solid substitution method with physical vapor deposition and microwave plasma chemical vapor deposition equipment. The density functional theory (DFT) is used to analyze the stability, electronic structure, and co-doping of N, Si, and O on the related defect structure of a rare Earth element yttrium-doped diamond using first-principle calculations, demonstrating consistency with the experimental results. The research shows that the fluorescence wavelength of an yttrium vacancy color center measured using the solid substitution method is 701.2 nm, which is located in the red region. The system is most stable when a Y atom replaces a carbon atom and there are two vacancies around it. The zero-phonon line of the diamond YV2 defect is predicted to be 708.855 nm. Additionally, the influence doping is analyzed with N, Si, and O atoms. An yttrium-doped diamond emits light in the visible light region, which provides a theoretical basis for the application of diamond yttrium vacancy color centers.
First-principles analyses are performed on the diamond europium vacancy (EuV) color center. Three different models indicate that the structure of the EuV color center contains a stable vacancy around the Eu atom. Energy band calculations show that the stable EuV color center has spin polarization and its spin-up energy level structure is highly suitable as a single-photon source. The zero-point transition energy is 1.989 eV (623 nm). The existence of metastable energy levels in the EuV is also predicted. Nitrogen atoms have a negative impact on the electronic structure of the EuV, in comparison to diamond color centers such as NE8 and TiV-N.
Atomic-sized fluorescent defects in diamond are widely recognized as a promising solid state platform for quantum cryptography and quantum information processing. For these applications, single photon sources with a high intensity and reproducible fabrication methods are required. In this study, we report a novel color center in diamond, composed of a germanium (Ge) and a vacancy (V) and named the GeV center, which has a sharp and strong photoluminescence band with a zero-phonon line at 602 nm at room temperature. We demonstrate this new color center works as a single photon source. Both ion implantation and chemical vapor deposition techniques enabled fabrication of GeV centers in diamond. A first-principles calculation revealed the atomic crystal structure and energy levels of the GeV center.
Color centers in diamond are widely recognized as a promising solid state platform for quantum cryptography and quantum information processing. For these applications, single photon sources with a high intensity and reproducible fabrication methods are required. Here, we report a novel color center in diamond, composed of a germanium (Ge) and a vacancy (V) and named the GeV center, which has a sharp and strong photoluminescence band with a zero-phonon line at 602 nm at room temperature. We demonstrate this new color center works as a single photon source. Both ion implantation and chemical vapor deposition techniques enabled fabrication of GeV centers in diamond. A first-principles calculation revealed the atomic crystal structure and energy levels of the GeV center.
We performed first-principles calculations to characterize the structure and electronic properties of Cr-related centers in diamond when oxygen or nitrogen is involved. We found that Cr2V-NC center with Cs symmetry is energetically favored under N-rich condition, with respect to Crint, CrC, Cr2V, and Cr2V-OC. In analogy to the Cr2V defect, Cr2V-NC center also introduces strongly spin polarized impurity levels into the diamond band, in favor of single-photon emission. The yield of optically active centers of the single photon emitters could be improved by incorporation of N, since the formation energy of Cr2V-NC complex is lower than that of Cr2V under N rich condition. Meanwhile, our calculations indicated that the additional incorporation of O to Cr or (Cr, N) defects introduces not well-separated impurity levels, which will broaden the emission lines.
Color centers in diamond have emerged as leading solid-state ``artificial atoms'' for a range of quantum technologies, from quantum sensing to quantum networks. Concerted research activities are now underway to identify new color centers that combine stable spin and optical properties of the nitrogen vacancy (${\mathrm{NV}}^{\ensuremath{-}}$) with the spectral stability of the silicon vacancy (${\mathrm{SiV}}^{\ensuremath{-}}$) centers in diamond, with recent research identifying other group-IV color centers with superior properties. In this paper, we investigate a class of diamond quantum emitters from first principles, the group-III color centers, which we show to be thermodynamically stable in a spin-1, electric-field-insensitive structure. From ab initio electronic structure methods, we characterize the product Jahn-Teller (pJT) effect present in the excited-state manifold of these group-III color centers, where we capture symmetry-breaking distortions associated with strong electron-phonon coupling. These predictions can guide experimental identification of group-III vacancy centers and their use in applications in quantum information science and technology.