Showing papers on "Diamond published in 2017"
Journal Article•
TL;DR: An integrated platform for scalable quantum nanophotonics based on silicon-vacancy color centers coupled to diamond nanodevices is demonstrated and a quantum interference effect resulting from the superradiant emission of two entangled SiV centers is observed.
Abstract: Integrated quantum nanophotonics Technologies that exploit the rules of quantum mechanics offer a potential advantage over classical devices in terms of sensitivity. Sipahigil et al. combined the quantum optical features of silicon-vacancy color centers with diamond-based photonic cavities to form a platform for integrated quantum nanophotonics (see the Perspective by Hanson). They could thus generate single photons from the color centers, optically switch light in the cavity by addressing the state of the color center, and quantum-mechanically entangle two color centers positioned in the cavity. The work presents a viable route to develop an integrated platform for quantum networks. Science, this issue p. 847; see also p. 835 An integrated quantum optical platform is demonstrated using silicon vacancy color centers and diamond photonics. Efficient interfaces between photons and quantum emitters form the basis for quantum networks and enable optical nonlinearities at the single-photon level. We demonstrate an integrated platform for scalable quantum nanophotonics based on silicon-vacancy (SiV) color centers coupled to diamond nanodevices. By placing SiV centers inside diamond photonic crystal cavities, we realize a quantum-optical switch controlled by a single color center. We control the switch using SiV metastable states and observe optical switching at the single-photon level. Raman transitions are used to realize a single-photon source with a tunable frequency and bandwidth in a diamond waveguide. By measuring intensity correlations of indistinguishable Raman photons emitted into a single waveguide, we observe a quantum interference effect resulting from the superradiant emission of two entangled SiV centers.
271 citations
TL;DR: In this paper, a negatively charged nitrogen-vacancy (NV−) center is created in diamond by laser writing (with pulses with a central wavelength of 790 nm and duration of 300 fs) with an accuracy of 200 nm in the transverse plane.
Abstract: A negatively charged nitrogen–vacancy centre — a promising quantum light source — is created in diamond by laser writing (with pulses with a central wavelength of 790 nm and duration of 300 fs) with an accuracy of 200 nm in the transverse plane. Optically active point defects in crystals have gained widespread attention as photonic systems that could be applied in quantum information technologies1,2. However, challenges remain in the placing of individual defects at desired locations, an essential element of device fabrication. Here we report the controlled generation of single negatively charged nitrogen–vacancy (NV−) centres in diamond using laser writing3. Aberration correction in the writing optics allows precise positioning of the vacancies within the diamond crystal, and subsequent annealing produces single NV− centres with a probability of success of up to 45 ± 15%, located within about 200 nm of the desired position in the transverse plane. Selected NV− centres display stable, coherent optical transitions at cryogenic temperatures, a prerequisite for the creation of distributed quantum networks of solid-state qubits. The results illustrate the potential of laser writing as a new tool for defect engineering in quantum technologies, and extend laser processing to the single-defect domain.
227 citations
TL;DR: In this paper, a composite of single-wall carbon nanotubes (SWCNT) with diamond nanoparticles and a SWCNT paper coated with nanocrystalline diamond films is studied.
221 citations
TL;DR: In this article, single-spin magnetometry is used for nonperturbative, nanoscale characterization of spin chemical potentials, which characterizes the tendency of spins to diffuse.
Abstract: The spin chemical potential characterizes the tendency of spins to diffuse. Probing this quantity could provide insight into materials such as magnetic insulators and spin liquids and aid optimization of spintronic devices. Here we introduce single-spin magnetometry as a generic platform for nonperturbative, nanoscale characterization of spin chemical potentials. We experimentally realize this platform using diamond nitrogen-vacancy centers and use it to investigate magnons in a magnetic insulator, finding that the magnon chemical potential can be controlled by driving the system’s ferromagnetic resonance. We introduce a symmetry-based two-fluid theory describing the underlying magnon processes, measure the local thermomagnonic torque, and illustrate the detection sensitivity using electrically controlled spin injection. Our results pave the way for nanoscale control and imaging of spin transport in mesoscopic systems.
199 citations
TL;DR: Direct, maskless creation of atom-like single silicon vacancy (SiV) centres in diamond nanostructures via focused ion beam implantation with ∼32 nm lateral precision and <50nm positioning accuracy relative to a nanocavity is demonstrated.
Abstract: The controlled creation of defect centre—nanocavity systems is one of the outstanding challenges for efficiently interfacing spin quantum memories with photons for photon-based entanglement operations in a quantum network Here we demonstrate direct, maskless creation of atom-like single silicon vacancy (SiV) centres in diamond nanostructures via focused ion beam implantation with ∼32 nm lateral precision and <50 nm positioning accuracy relative to a nanocavity We determine the Si+ ion to SiV centre conversion yield to be ∼25% and observe a 10-fold conversion yield increase by additional electron irradiation Low-temperature spectroscopy reveals inhomogeneously broadened ensemble emission linewidths of ∼51 GHz and close to lifetime-limited single-emitter transition linewidths down to 126±13 MHz corresponding to ∼14 times the natural linewidth This method for the targeted generation of nearly transform-limited quantum emitters should facilitate the development of scalable solid-state quantum information processors Interfacing spin quantum memories with photons requires the controlled creation of defect centre—nanocavity systems Here the authors demonstrate direct, maskless creation of single silicon vacancy centres in diamond nanostructures, and report linewidths comparable to naturally occurring centres
198 citations
TL;DR: These measurements constrain possible defect models and suggest that several classes of emitters can exist simultaneously throughout free-standing h-BN, whether they be different defects, different charge states of the same defect, or the result of strong local perturbations.
Abstract: Hexagonal boron nitride (h-BN) is rapidly emerging as an attractive material for solid-state quantum engineering. Analogously to three-dimensional wide-band-gap semiconductors such as diamond, h-BN hosts isolated defects exhibiting visible fluorescence at room temperature, and the ability to position such quantum emitters within a two-dimensional material promises breakthrough advances in quantum sensing, photonics, and other quantum technologies. Critical to such applications is an understanding of the physics underlying h-BN’s quantum emission. We report the creation and characterization of visible single-photon sources in suspended, single-crystal, h-BN films. With substrate interactions eliminated, we study the spectral, temporal, and spatial characteristics of the defects’ optical emission. Theoretical analysis of the defects’ spectra reveals similarities in vibronic coupling to h-BN phonon modes despite widely varying fluorescence wavelengths, and a statistical analysis of the polarized emission fro...
191 citations
TL;DR: In this paper, optical and electron-spin properties of a germanium-vacancy defect in diamond were presented, where the defect center combines high brightness and exceptional spectral stability with microwave and optical access to electron spin.
Abstract: Novel solid-state qubits have a lot to offer for quantum information processing because of the potential simplicity of engineering quantum computational hardware similar to modern silicon-based electronics. This work presents optical and electron-spin properties of a novel germanium-vacancy defect in diamond. The defect center combines high brightness and exceptional spectral stability with microwave and optical access to electron spin. The combination of a spin-\textonehalf{} qubit and an optical interface makes possible of the germanium-vacancy defect in scalable quantum networks.
172 citations
TL;DR: In this paper, the authors highlight recent advances in free-standing wide band-gap membranes, including GaN, SiC, ZnO, β-Ga2O3, and diamond and their applications.
Abstract: Free-standing single crystalline semiconductor membranes have gained intensive attention over the last few years due to their versatile usage in many applications. This material platform possesses a high level of material quality similar to their bulk counterparts because single crystallinity is maintained. Si, Ge, and III–V based membranes have been widely studied for flexible electronic and optoelectronic devices such as thin-film transistors and photodetectors. However, the current status of research and development on free-standing single crystalline wide band-gap membranes is at a relatively early stage compared to IV and III–V based membranes. This review highlights recent advances in free-standing wide band-gap membranes, including GaN, SiC, ZnO, β-Ga2O3, and diamond and their applications. Fabrication techniques of each membrane are presented with material characterization. Some prospects for new research opportunities and challenges are also discussed.
154 citations
TL;DR: In this paper, a uniform wear layer of 48 nm in thickness was obtained on a silicon wafer ground by the C2 at a feed rate of 12μm/min, which is less than one third that formed by a conventional diamond wheel with mesh size of 5000.
150 citations
TL;DR: The Planetary Major Equipment Program (NNX15AH72G) as discussed by the authors is a program of the U.S. National Aeronautics and Space Administration (NOAASA).
Abstract: United States. National Aeronautics and Space Administration. Planetary Major Equipment Program (NNX15AH72G)
149 citations
TL;DR: In this article, the authors demonstrate on-chip diamond nanophotonics with a high-efficiency fiber-optic interface, achieving g90% power coupling at visible wavelengths.
Abstract: The authors demonstrate on-chip diamond nanophotonics with a high-efficiency fiber-optic interface, achieving g90% power coupling at visible wavelengths. They use this approach to create a bright source of narrowband single photons, based on a silicon-vacancy color center embedded in a waveguide-coupled diamond photonic-crystal cavity. Their quantum nanophotonic interface yields a high flux of coherent single photons into a single-mode fiber, enabling possibilities for quantum networks that couple multiple emitters, either on the same chip or separated by long distances.
TL;DR: It is shown that a diamond single crystal with a diameter of ~90 mm and a weight of 155 carat can be grown from such a carbon film which initially consisted of 2 · 1013 individual grains.
Abstract: A detailed mechanism for heteroepitaxial diamond nucleation under ion bombardment in a microwave plasma enhanced chemical vapour deposition setup on the single crystal surface of iridium is presented. The novel mechanism of Ion Bombardment Induced Buried Lateral Growth (IBI-BLG) is based on the ion bombardment induced formation and lateral spread of epitaxial diamond within a ~1 nm thick carbon layer. Starting from one single primary nucleation event the buried epitaxial island can expand laterally over distances of several microns. During this epitaxial lateral growth typically thousands of isolated secondary nuclei are generated continuously. The unique process is so far only observed on iridium surfaces. It is shown that a diamond single crystal with a diameter of ~90 mm and a weight of 155 carat can be grown from such a carbon film which initially consisted of 2 · 1013 individual grains.
TL;DR: It is demonstrated that atomic-like impurities in diamond can be used to probe the properties of 2D materials by nanometer-scale nuclear quadrupole resonance spectroscopy, which could enable the development of new quantum hybrid systems.
Abstract: Two-dimensional (2D) materials offer a promising platform for exploring condensed matter phenomena and developing technological applications. However, the reduction of material dimensions to the atomic scale poses a challenge for traditional measurement and interfacing techniques that typically couple to macroscopic observables. We demonstrate a method for probing the properties of 2D materials via nanometer-scale nuclear quadrupole resonance (NQR) spectroscopy using individual atomlike impurities in diamond. Coherent manipulation of shallow nitrogen-vacancy (NV) color centers enables the probing of nanoscale ensembles down to approximately 30 nuclear spins in atomically thin hexagonal boron nitride (h-BN). The characterization of low-dimensional nanoscale materials could enable the development of new quantum hybrid systems, combining atomlike systems coherently coupled with individual atoms in 2D materials.
TL;DR: In this article, a partially oxidized (partial C-O) channel was used for hydrogen-terminated (C-H) diamond MOSFETs with a high breakdown voltage of over 2 kV at room temperature and normally-off characteristics with a gate threshold voltage of −2.5 −−4 V.
Abstract: Diamond has unique physical properties, which show great promise for applications in the next generation power devices. Hydrogen-terminated (C–H) diamond metal–oxide–semiconductor field-effect transistors (MOSFETs) often have normally-on operation in devices, because the C–H channel features a p-type inversion layer; however, normally-off devices are preferable in power MOSFETs from the viewpoint of fail safety. We fabricated hydrogen-terminated (C–H) diamond MOSFETs using a partially oxidized (partial C–O) channel. The fabricated MOSFETs showed a high breakdown voltage of over 2 kV at room temperature and normally-off characteristics with a gate threshold voltage $\text{V}_{\mathrm{th}}$ of −2.5–−4 V.
TL;DR: Spectroscopic evidence for the formation of diamondene is provided by performing Raman spectroscopy of double-layer graphene under high pressure and is explained in terms of a breakdown in the Kohn anomaly associated with the finite size of the remaining graphene sites surrounded by the diamondene matrix.
Abstract: Despite the advanced stage of diamond thin-film technology, with applications ranging from superconductivity to biosensing, the realization of a stable and atomically thick two-dimensional diamond material, named here as diamondene, is still forthcoming. Adding to the outstanding properties of its bulk and thin-film counterparts, diamondene is predicted to be a ferromagnetic semiconductor with spin polarized bands. Here, we provide spectroscopic evidence for the formation of diamondene by performing Raman spectroscopy of double-layer graphene under high pressure. The results are explained in terms of a breakdown in the Kohn anomaly associated with the finite size of the remaining graphene sites surrounded by the diamondene matrix. Ab initio calculations and molecular dynamics simulations are employed to clarify the mechanism of diamondene formation, which requires two or more layers of graphene subjected to high pressures in the presence of specific chemical groups such as hydroxyl groups or hydrogens. The synthesis of two-dimensional diamond is the ultimate goal of diamond thin-film technology. Here, the authors perform Raman spectroscopy of bilayer graphene under pressure, and obtain spectroscopic evidence of formation of diamondene, an atomically thin form of diamond.
TL;DR: In this paper, the neutral charge state of silicon vacancy (SiV0) was proposed as a color center with insensitivity to both phonon- mediated spin relaxation and electric field noise.
Abstract: Engineering coherent systems is a central goal of quantum science. Color centers in diamond are a promising approach, with the potential to combine the coherence of atoms with the scalability of a solid state platform. However, the solid environment can adversely impact coherence. For example, phonon- mediated spin relaxation can induce spin decoherence, and electric field noise can change the optical transition frequency over time. We report a novel color center with insensitivity to both of these sources of environmental decoherence: the neutral charge state of silicon vacancy (SiV0). Through careful material engineering, we achieve over 80% conversion of implanted silicon to SiV0. SiV0 exhibits excellent spin properties, with spin-lattice relaxation times (T1) approaching one minute and coherence times (T2) approaching one second, as well as excellent optical properties, with approximately 90% of its emission into the zero-phonon line and near-transform limited optical linewidths. These combined properties make SiV0 a promising defect for quantum networks.
18 Jul 2017
TL;DR: In this paper, the performance of GaN/GaN high-electron-mobility transistors (HEMTs) on diamond and SiC substrates was examined, and GaN-on-diamond transistors with periphery WG = 250 mum, exhibiting ft = 27.4 GHz and yielding a power density of 2.79 W/mm at 10 GHz.
Abstract: The performance of AlGaN/GaN high-electron-mobility transistors (HEMTs) on diamond and SiC substrates is examined. We demonstrate GaN-on-diamond transistors with periphery WG = 250 mum, exhibiting ft = 27.4 GHz and yielding a power density of 2.79 W/mm at 10 GHz. Additionally, the temperature rise in similar devices on diamond and SiC substrates is reported. To the best of our knowledge, these represent the highest frequency of operation and first-reported thermal and X -band power measurements of GaN-on-diamond HEMTs.
TL;DR: In this paper, the effect of grain wear on material removal behavior during grinding nickel-based superalloy Inconel 718 was investigated under the conditions of undeformed chip thickness (UCT) ranging from 0.2 to 1 µm.
Abstract: In order to explore the effect of grain wear on material removal behavior during grinding nickel-based superalloy Inconel 718, the grinding experiment with a single diamond grain was carried out. The variations of grain wear, grinding force and force ratio, and pile-up ratio were investigated under the conditions of undeformed chip thickness (UCT) ranging from 0.2 to 1 µm. The results show that a critical UCT value, such as 0.3 µm, could be determined according to the pile-up ratio and could also be used to quantify the material removal process. The wear behavior of a diamond grain shows four types, such as crescent depression on the rake face, abrasion on the flank face, grain micro-fracture, and grain macro-fracture. Furthermore, these classifications are determined by the dwell time of rubbing, ploughing and cutting at different UCT values applied. The grinding force ratio increases with increasing of the negative rake angle of a diamond grain. In the rubbing and ploughing stages, the material removal efficiency is proportional to the wear width on the rake face. However, in the cutting stage, the material removal efficiency is diminished in the absence process of crescent depression.
TL;DR: In this article, the microstructure and thermal properties of the composites prepared by a vacuum pressure infiltration method were investigated and a promising approach to improve performance of diamond reinforced metal matrix composites by selecting carbide as an interface modifier was proposed.
TL;DR: It is shown that the charge state of implantation-induced defects drastically influences the formation of lattice defects during thermal annealing, resulting in tenfold- improved spin coherence times and twofold-improved formation yield of nitrogen-vacancy centres in diamond.
Abstract: Atomic-size spin defects in solids are unique quantum systems. Most applications require nanometre positioning accuracy, which is typically achieved by low-energy ion implantation. A drawback of this technique is the significant residual lattice damage, which degrades the performance of spins in quantum applications. Here we show that the charge state of implantation-induced defects drastically influences the formation of lattice defects during thermal annealing. Charging of vacancies at, for example, nitrogen implantation sites suppresses the formation of vacancy complexes, resulting in tenfold-improved spin coherence times and twofold-improved formation yield of nitrogen-vacancy centres in diamond. This is achieved by confining implantation defects into the space-charge layer of free carriers generated by a boron-doped diamond structure. By combining these results with numerical calculations, we arrive at a quantitative understanding of the formation and dynamics of the implanted spin defects. These results could improve engineering of quantum devices using solid-state systems.
TL;DR: In this paper, a high-quality carbide interface between the metal matrix and diamond was used to improve the bulk thermal conductivity of composite materials, achieving an ITCDEM of 5·107 Wm−m−2 K−K−1.
TL;DR: In this article, a diamond-reinforced metal matrix composites (DMMC) was applied to aluminum alloy substrate via cold spray of three feedstock powders: copper-clad diamond and pure copper, and their mixtures.
Abstract: Diamond-reinforced metal matrix composites (DMMC) have great potential for wear-resistance applications due to the superior hardness of the diamond component. Cold spray as an emerging coating technique is able to fabricate coatings or bulk materials without exceeding the material melting point, thereby significantly lowering the risk of oxidation, phase transformation, and excessive thermal residual stress. In this paper, thick DMMC coatings were deposited onto aluminum alloy substrate via cold spray of three feedstock powders: copper-clad diamond and pure copper, and their mixtures. It was found that, due to its low processing temperature, cold spray is able to prevent graphitization of the diamond in the DMMC coatings. Further to that, the original diamond phase was almost completely retained in the DMMC coatings. In case of the coatings fabricated from copper-clad diamond powders only, its mass fraction reached 43 wt.%, i.e. value higher than in any previous studies using conventional pre-mixed powders. Furthermore, it was found that the added copper content powders acted as a buffer, effectively preventing the fracture of the diamond particles in the coating. Finally, the wear test on the coatings showed that the cold sprayed DMMC coatings had excellent wear-resistance properties due to the diamond reinforcement.
TL;DR: The quantum diamond microscope (QDM) as mentioned in this paper uses nitrogen-vacancy centers in diamond to enable direct imaging of magnetic fields due to both remanent and induced magnetization, as well as optical imaging, of room-temperature geological samples with spatial resolution approaching the optical diffraction limit.
Abstract: Remanent magnetization in geological samples may record the past intensity and direction of planetary magnetic fields. Traditionally, this magnetization is analyzed through measurements of the net magnetic moment of bulk millimeter to centimeter sized samples. However, geological samples are often mineralogically and texturally heterogeneous at submillimeter scales, with only a fraction of the ferromagnetic grains carrying the remanent magnetization of interest. Therefore, characterizing this magnetization in such cases requires a technique capable of imaging magnetic fields at fine spatial scales and with high sensitivity. To address this challenge, we developed a new instrument, based on nitrogen-vacancy centers in diamond, which enables direct imaging of magnetic fields due to both remanent and induced magnetization, as well as optical imaging, of room-temperature geological samples with spatial resolution approaching the optical diffraction limit. We describe the operating principles of this device, which we call the quantum diamond microscope (QDM), and report its optimized image-area-normalized magnetic field sensitivity (20 uT.um/Hz^1/2), spatial resolution (5 um), and field of view (4 mm), as well as trade-offs between these parameters. We also perform an absolute magnetic field calibration for the device in different modes of operation, including three-axis (vector) and single-axis (projective) magnetic field imaging. Finally, we use the QDM to obtain magnetic images of several terrestrial and meteoritic rock samples, demonstrating its ability to resolve spatially distinct populations of ferromagnetic carriers.
TL;DR: The results pave the way towards a systematic study of SR in a well-controlled, solid-state quantum system at room temperature from single, highly luminescent diamond nanocrystals with spatial dimensions much smaller than the wavelength of light.
Abstract: Superradiance (SR) is a cooperative phenomenon which occurs when an ensemble of quantum emitters couples collectively to a mode of the electromagnetic field as a single, massive dipole that radiates photons at an enhanced rate. Previous studies on solid-state systems either reported SR from sizeable crystals with at least one spatial dimension much larger than the wavelength of the light and/or only close to liquid-helium temperatures. Here, we report the observation of room-temperature superradiance from single, highly luminescent diamond nanocrystals with spatial dimensions much smaller than the wavelength of light, and each containing a large number (~ 103) of embedded nitrogen-vacancy (NV) centres. The results pave the way towards a systematic study of SR in a well-controlled, solid-state quantum system at room temperature. Previously, superradiance was observed from sizeable crystals or close to liquid-helium temperatures. Here, Bradec et al. report the observation of room-temperature superradiance from single, highly luminescent diamond nanocrystals with spatial dimensions much smaller than the wavelength of light.
TL;DR: The superior properties of diamond nanomaterials and the nitrogen-vacancy centers they contain as well as their uses in biomedical applications, including biosensing, bioimaging and drug delivery are reviewed.
Abstract: Diamond features an attractive combination of outstanding mechanical, optical, thermal and electrical properties; tunable surface characteristics; and unprecedented biocompatibility. Additionally, diamond can possess unique nitrogen–vacancy emission centers that are highly photostable and extremely sensitive to magnetic fields, temperatures, ion concentrations, and spin densities. With these inherent merits, diamond in various nanoscale configurations has demonstrated a variety of distinctive applications in a broad range of fields. In particular, research on diamond nanoparticles (0-dimensional structures) and arrays of diamond nanoneedles/nanowires (1-dimensional structures) has witnessed important and exciting progress in recent years. Here, we systematically review the superior properties of diamond nanomaterials and the nitrogen–vacancy centers they contain as well as their uses in biomedical applications, including biosensing, bioimaging and drug delivery. Moreover, systematic studies of the biocompatibility and toxicity of diamond nanostructures, which constitute an important issue for the biomedical applications of diamond that has not yet been thoroughly addressed in previous reviews, are also discussed. Finally, we present our insights into the key issues concerning these diamond nanomaterials and their future development for applications.
TL;DR: In this paper, the authors studied the properties of boron-doped diamond layers with metallic conduction and found that the position of the main Raman bands is proportional to borone concentration, and attributed the downshift and broadening of the diamond line to the domain size effect caused by scattering on borons impurities, secondly to the Fano effect due to electronic Raman interaction, and finally to lattice expansion.
TL;DR: In this article, a magnetic resonance signal is detected by probing absorption on the 1042-nm spin-singlet transition, which is placed in an optical resonator to improve the absorptive signal.
Abstract: We present a highly sensitive miniaturized cavity-enhanced room-temperature magnetic-field sensor based on nitrogen-vacancy centers in diamond. The magnetic resonance signal is detected by probing absorption on the 1042-nm spin-singlet transition. To improve the absorptive signal the diamond is placed in an optical resonator. The device has a magnetic-field sensitivity of 28 pT/Hz, a projected photon shot-noise-limited sensitivity of 22 pT/Hz, and an estimated quantum projection-noise-limited sensitivity of 0.43 pT/Hz with the sensing volume of ∼390 μm×4500 μm2. The presented miniaturized device is the basis for an endoscopic magnetic-field sensor for biomedical applications.
TL;DR: This work demonstrates a simple approach for spontaneously growing double-diamond crystals that contain a suitable diamond structure, using DNA to direct the self-assembly process and suggests that other unexpected microstructures may be accessible using this approach.
Abstract: Future optical materials promise to do for photonics what semiconductors did for electronics, but the challenge has long been in creating the structure they require-a regular, three-dimensional array of transparent microspheres arranged like the atoms in a diamond crystal. Here we demonstrate a simple approach for spontaneously growing double-diamond (or B32) crystals that contain a suitable diamond structure, using DNA to direct the self-assembly process. While diamond symmetry crystals have been grown from much smaller nanoparticles, none of those previous methods suffice for the larger particles needed for photonic applications, whose size must be comparable to the wavelength of visible light. Intriguingly, the crystals we observe do not readily form in previously validated simulations; nor have they been predicted theoretically. This finding suggests that other unexpected microstructures may be accessible using this approach and bodes well for future efforts to inexpensively mass-produce metamaterials for an array of photonic applications.
TL;DR: The fabrication of luminescent defects in single-crystal diamond upon diamond implantation and annealing is reported in this paper, where the relevant spectral features of the optical centers (emission peaks at 593.5, 620.7, and 646.7 nm) are attributed to Sn-related defects through the correlation of their photoluminescence (PL) intensity with the implantation fluence.
Abstract: The fabrication of luminescent defects in single-crystal diamond upon Sn implantation and annealing is reported. The relevant spectral features of the optical centers (emission peaks at 593.5, 620.3, 630.7, and 646.7 nm) are attributed to Sn-related defects through the correlation of their photoluminescence (PL) intensity with the implantation fluence. Single Sn-related defects were identified and characterized through the acquisition of their second-order autocorrelation emission functions, by means of Hanbury-Brown and Twiss interferometry. The investigation of their single-photon emission regime as a function of excitation laser power revealed that Sn-related defects are based on three-level systems with a 6 ns radiative decay lifetime. In a fraction of the studied centers, the observation of a blinking PL emission is indicative of the existence of a dark state. Furthermore, absorption dependence on the polarization of the excitation radiation with ∼45% contrast was measured. This work shed light on th...
TL;DR: In this paper, a microcavity scheme for nitrogen-vacancy (NV) centers in diamond was proposed, which uses minimally processed diamond, thereby preserving the high quality of the starting material, and a tunable microcavaity platform.
Abstract: The nitrogen-vacancy (NV) center in diamond has an optically addressable, highly coherent spin. However, an NV center even in high quality single-crystalline material is a very poor source of single photons: extraction out of the high-index diamond is inefficient, the emission of coherent photons represents just a few per cent of the total emission, and the decay time is large. In principle, all three problems can be addressed with a resonant microcavity. In practice, it has proved difficult to implement this concept: photonic engineering hinges on nano-fabrication yet it is notoriously difficult to process diamond without degrading the NV centers. We present here a microcavity scheme which uses minimally processed diamond, thereby preserving the high quality of the starting material, and a tunable microcavity platform. We demonstrate a clear change in the lifetime for multiple individual NV centers on tuning both the cavity frequency and anti-node position, a Purcell effect. The overall Purcell factor $F_{\rm P}=2.0$ translates to a Purcell factor for the zero phonon line (ZPL) of $F_{\rm P}^{\rm ZPL}\sim30$ and an increase in the ZPL emission probability from $\sim 3 \%$ to $\sim 46 \%$. By making a step-change in the NV's optical properties in a deterministic way, these results pave the way for much enhanced spin-photon and spin-spin entanglement rates.