Showing papers on "Diamond published in 2016"
TL;DR: In this paper, the authors demonstrate room-temperature, polarized and ultrabright single-photon emission from a color center in two-dimensional hexagonal boron nitride.
Abstract: Artificial atomic systems in solids are widely considered the leading physical system for a variety of quantum technologies, including quantum communications, computing and metrology. To date, however, room-temperature quantum emitters have only been observed in wide-bandgap semiconductors such as diamond and silicon carbide, nanocrystal quantum dots, and most recently in carbon nanotubes. Single-photon emission from two-dimensional materials has been reported, but only at cryogenic temperatures. Here, we demonstrate room-temperature, polarized and ultrabright single-photon emission from a colour centre in two-dimensional hexagonal boron nitride. Density functional theory calculations indicate that vacancy-related defects are a probable source of the emission. Our results demonstrate the unprecedented potential of van der Waals crystals for large-scale nanophotonics and quantum information processing.
761 citations
TL;DR: In this article, the authors demonstrate an integrated platform for scalable quantum nanophotonics based on silicon-vacancy (SiV) color centers coupled to diamond nanodevices.
Abstract: 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.
583 citations
TL;DR: In this article, the authors demonstrate an integrated platform for scalable quantum nanophotonics based on silicon-vacancy (SiV) color centers coupled to nanoscale diamond devices.
Abstract: Efficient interfaces between photons and quantum emitters form the basis for quantum networks and enable nonlinear optical devices operating at the single-photon level. We demonstrate an integrated platform for scalable quantum nanophotonics based on silicon-vacancy (SiV) color centers coupled to nanoscale diamond devices. 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 orbital states and verify optical switching at the single-photon level by using photon correlation measurements. We use Raman transitions to realize a single-photon source with a tunable frequency and bandwidth in a diamond waveguide. Finally, we create entanglement between two SiV centers by detecting indistinguishable Raman photons emitted into a single waveguide. Entanglement is verified using a novel superradiant feature observed in photon correlation measurements, paving the way for the realization of quantum networks.
435 citations
TL;DR: A strategy for creating a diamond superlattice of nano-objects via self-assembly is reported and its experimental realization is demonstrated by assembling two variant diamond lattices, one with and one without atomic analogs.
Abstract: Diamond lattices formed by atomic or colloidal elements exhibit remarkable functional properties. However, building such structures via self-assembly has proven to be challenging because of the low packing fraction, sensitivity to bond orientation, and local heterogeneity. We report a strategy for creating a diamond superlattice of nano-objects via self-assembly and demonstrate its experimental realization by assembling two variant diamond lattices, one with and one without atomic analogs. Our approach relies on the association between anisotropic particles with well-defined tetravalent binding topology and isotropic particles. The constrained packing of triangular binding footprints of truncated tetrahedra on a sphere defines a unique three-dimensional lattice. Hence, the diamond self-assembly problem is solved via its mapping onto two-dimensional triangular packing on the surface of isotropic spherical particles.
324 citations
TL;DR: Diamond quantum sensors based on the spin-dependent photoluminescence of nitrogen-vacancy centers in diamond offer great potential to achieve single-molecule detection with atomic resolution under ambient conditions and might provide unprecedented access and insight into the structure and function of individual biomolecules under physiological conditions.
Abstract: The currently available techniques for molecular imaging capable of reaching atomic resolution are limited to low temperatures, vacuum conditions, or large amounts of sample. Quantum sensors based on the spin-dependent photoluminescence of nitrogen-vacancy (NV) centers in diamond offer great potential to achieve single-molecule detection with atomic resolution under ambient conditions. Diamond nanoparticles could also be prepared with implanted NV centers, thereby generating unique nanosensors that are able to traffic into living biological systems. Therefore, this technique might provide unprecedented access and insight into the structure and function of individual biomolecules under physiological conditions as well as observation of biological processes down to the quantum level with atomic resolution. The theory of diamond quantum sensors and the current developments from their preparation to sensing techniques have been critically discussed in this Minireview.
216 citations
TL;DR: A review of recent advances in diamond nano-and microphotonic structures for efficient light collection, color center to nanocavity coupling, hybrid integration of diamond devices with other material systems, and the wide range of fabrication methods that have enabled these complex photonic diamond systems can be found in this article.
Abstract: The past two decades have seen great advances in developing color centers in diamond for sensing, quantum information processing, and tests of quantum foundations. Increasingly, the success of these applications as well as fundamental investigations of light–matter interaction depend on improved control of optical interactions with color centers—from better fluorescence collection to efficient and precise coupling with confined single optical modes. Wide ranging research efforts have been undertaken to address these demands through advanced nanofabrication of diamond. This review will cover recent advances in diamond nano- and microphotonic structures for efficient light collection, color center to nanocavity coupling, hybrid integration of diamond devices with other material systems, and the wide range of fabrication methods that have enabled these complex photonic diamond systems.
214 citations
TL;DR: A review of diamond nanoelectrochemistry can be found in this article, where a brief introduction of synthetic strategies to form diamond nanostructures and particles, their electrochemical properties in the presence and absence of redox probes are shown, followed by their use in electrochemical, biochemical sensing, etc.
185 citations
TL;DR: In this article, cubic, diamond and reentrant cube lattice structures were tested under quasi-static conditions to investigate failure process and stress-strain response of such materials.
175 citations
TL;DR: This experiment provides new insights into the processes of the shock-induced transition from graphite to diamond and uniquely resolves the dynamics that explain the main natural occurrence of the lonsdaleite crystal structure being close to meteor impact sites.
Abstract: The shock-induced transition from graphite to diamond has been of great scientific and technological interest since the discovery of microscopic diamonds in remnants of explosively driven graphite. Furthermore, shock synthesis of diamond and lonsdaleite, a speculative hexagonal carbon polymorph with unique hardness, is expected to happen during violent meteor impacts. Here, we show unprecedented in situ X-ray diffraction measurements of diamond formation on nanosecond timescales by shock compression of pyrolytic as well as polycrystalline graphite to pressures from 19 GPa up to 228 GPa. While we observe the transition to diamond starting at 50 GPa for both pyrolytic and polycrystalline graphite, we also record the direct formation of lonsdaleite above 170 GPa for pyrolytic samples only. Our experiment provides new insights into the processes of the shock-induced transition from graphite to diamond and uniquely resolves the dynamics that explain the main natural occurrence of the lonsdaleite crystal structure being close to meteor impact sites.
173 citations
TL;DR: In this article, the authors demonstrate a simple technique to create diamond color centers with uniformly high-quality optical properties, even inside nanoscale devices, which may well open the gates for quantum information processing based on this type of hardware.
Abstract: Color centers in diamond provide a promising platform for quantum optics in the solid state, but often their desirable properties are spoiled when they are incorporated into actual devices. The authors demonstrate a simple technique to create centers with uniformly high-quality optical properties, even inside nanoscale devices. Their method may well open the gates for quantum information processing based on this type of hardware.
169 citations
TL;DR: In this paper, an optimized procedure was presented to fabricate single-crystal, all-diamond scanning probes starting from commercially available diamond and show a highly efficient and robust approach for integrating these devices in a generic atomic force microscope.
Abstract: The electronic spin of the nitrogen vacancy (NV) center in diamond forms an atomically sized, highly sensitive sensor for magnetic fields. To harness the full potential of individual NV centers for sensing with high sensitivity and nanoscale spatial resolution, NV centers have to be incorporated into scanning probe structures enabling controlled scanning in close proximity to the sample surface. Here, we present an optimized procedure to fabricate single-crystal, all-diamond scanning probes starting from commercially available diamond and show a highly efficient and robust approach for integrating these devices in a generic atomic force microscope. Our scanning probes consisting of a scanning nanopillar (200 nm diameter, 1–2 μm length) on a thin (<1 μm) cantilever structure enable efficient light extraction from diamond in combination with a high magnetic field sensitivity (ηAC≈50±20nT/Hz). As a first application of our scanning probes, we image the magnetic stray field of a single Ni nanorod. We show that this stray field can be approximated by a single dipole and estimate the NV-to-sample distance to a few tens of nanometer, which sets the achievable resolution of our scanning probes.
TL;DR: It is shown that nitrogen-vacancy centers in diamond interfaced with a suspended carbon nanotube carrying a dc current can facilitate a spin-nanomechanical hybrid device.
Abstract: We show that nitrogen-vacancy (NV) centers in diamond interfaced with a suspended carbon nanotube carrying a dc current can facilitate a spin-nanomechanical hybrid device. We demonstrate that strong magnetomechanical interactions between a single NV spin and the vibrational mode of the suspended nanotube can be engineered and dynamically tuned by external control over the system parameters. This spin-nanomechanical setup with strong, intrinsic, and tunable magnetomechanical couplings allows for the construction of hybrid quantum devices with NV centers and carbon-based nanostructures, as well as phonon-mediated quantum information processing with spin qubits.
TL;DR: Inversion channel diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) with normally off characteristics are fabricated, indicating that an inversion channel with a p-type character was formed at a high-quality n-type diamond body/Al2O3 interface.
Abstract: We fabricated inversion channel diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) with normally off characteristics. At present, Si MOSFETs and insulated gate bipolar transistors (IGBTs) with inversion channels are widely used because of their high controllability of electric power and high tolerance. Although a diamond semiconductor is considered to be a material with a strong potential for application in next-generation power devices, diamond MOSFETs with an inversion channel have not yet been reported. We precisely controlled the MOS interface for diamond by wet annealing and fabricated p-channel and planar-type MOSFETs with phosphorus-doped n-type body on diamond (111) substrate. The gate oxide of Al2O3 was deposited onto the n-type diamond body by atomic layer deposition at 300 °C. The drain current was controlled by the negative gate voltage, indicating that an inversion channel with a p-type character was formed at a high-quality n-type diamond body/Al2O3 interface. The maximum drain current density and the field-effect mobility of a diamond MOSFET with a gate electrode length of 5 μm were 1.6 mA/mm and 8.0 cm2/Vs, respectively, at room temperature.
TL;DR: In this paper, the authors present a Quantum-Assisted Sensing and Readout Program (QARS) for the U.S. Defense Advanced Research Projects Agency (DARPA).
Abstract: United States. Defense Advanced Research Projects Agency. Quantum-Assisted Sensing and Readout Program
20 Dec 2016
TL;DR: In this article, the authors demonstrate diamond optomechanical crystals (OMCs), a device platform to enable such applications, wherein the co-localization of ∼200 THz photons and few to 10 GHz phonons in a quasi-periodic diamond nanostructure leads to coupling of an optical cavity field to a mechanical mode via radiation pressure.
Abstract: Cavity-optomechanical systems realized in single-crystal diamond are poised to benefit from its extraordinary material properties, including low mechanical dissipation and a wide optical transparency window. Diamond is also rich in optically active defects, such as the nitrogen-vacancy (NV) and silicon-vacancy (SiV) centers, which behave as atom-like systems in the solid state. Predictions and observations of coherent coupling of the NV electronic spin to phonons via lattice strain have motivated the development of diamond nanomechanical devices aimed at the realization of hybrid quantum systems in which phonons provide an interface with diamond spins. In this work, we demonstrate diamond optomechanical crystals (OMCs), a device platform to enable such applications, wherein the co-localization of ∼200 THz photons and few to 10 GHz phonons in a quasi-periodic diamond nanostructure leads to coupling of an optical cavity field to a mechanical mode via radiation pressure. In contrast to other material systems, diamond OMCs operating in the resolved-sideband regime possess large intracavity photon capacities (>10^5) and sufficient optomechanical coupling rates to reach a cooperativity of ∼20 at room temperature, allowing for the observation of optomechanically induced transparency and the realization of large-amplitude optomechanical self-oscillations.
TL;DR: In this paper, the authors use molecular dynamics simulation to study the mechanisms of plasticity during cutting of monocrystalline and polycrystalline silicon, showing that brittle cracking typically inclined at an angle of 45°-55° to the cut surface leads to the formation of periodic arrays of nanogrooves in monocrystine silicon.
TL;DR: In this paper, the authors present a clear target for the RD with a killer defect density less than 0.1 cm−2, resistivity less than ε 0.005 ε, and a size of 4in.
TL;DR: This work demonstrates fully three-dimensional and patterned localization of nitrogen-vacancy centers in diamond with coherence times in excess of 1 ms and enables the formation of reliably high-quality NV centers inside diamond nanostructures with applications in quantum information and sensing.
Abstract: We demonstrate fully three-dimensional and patterned localization of nitrogen-vacancy (NV) centers in diamond with coherence times in excess of 1 ms. Nitrogen δ-doping during chemical vapor deposition diamond growth vertically confines nitrogen to 4 nm while electron irradiation with a transmission electron microscope laterally confines vacancies to less than 450 nm. We characterize the effects of electron energy and dose on NV formation. Importantly, our technique enables the formation of reliably high-quality NV centers inside diamond nanostructures with applications in quantum information and sensing.
TL;DR: A method for measuring ESR spectra of nanoscale electronic environments by measuring the longitudinal relaxation time of a single-spin probe as it is systematically tuned into resonance with the target electronic system.
Abstract: Electron spin resonance (ESR) describes a suite of techniques for characterizing electronic systems with applications in physics, chemistry, and biology. However, the requirement for large electron spin ensembles in conventional ESR techniques limits their spatial resolution. Here we present a method for measuring ESR spectra of nanoscale electronic environments by measuring the longitudinal relaxation time of a single-spin probe as it is systematically tuned into resonance with the target electronic system. As a proof of concept, we extracted the spectral distribution for the P1 electronic spin bath in diamond by using an ensemble of nitrogen-vacancy centres, and demonstrated excellent agreement with theoretical expectations. As the response of each nitrogen-vacancy spin in this experiment is dominated by a single P1 spin at a mean distance of 2.7 nm, the application of this technique to the single nitrogen-vacancy case will enable nanoscale ESR spectroscopy of atomic and molecular spin systems.
TL;DR: In this paper, the photoluminescence of negatively charged nitrogen-vacancy centers is used to measure magnetic fields without the use of microwaves, which can be useful in applications where the sensor is placed close to conductive materials, e.g., magnetic induction tomography or magnetic field mapping, and in remote sensing applications since principally no electrical access is needed.
Abstract: We use magnetic-field-dependent features in the photoluminescence of negatively charged nitrogen-vacancy centers to measure magnetic fields without the use of microwaves. In particular, we present a magnetometer based on the level anti-crossing in the triplet ground state at 102.4 mT with a demonstrated noise floor of 6 nT/ Hz, limited by the intensity noise of the laser and the performance of the background-field power supply. The technique presented here can be useful in applications where the sensor is placed close to conductive materials, e.g., magnetic induction tomography or magnetic field mapping, and in remote-sensing applications since principally no electrical access is needed.
TL;DR: The first demonstration of three dimensional buried optical waveguides in diamond, inscribed by focused femtosecond high repetition rate laser pulses is reported, making them promising for integrated magnetometer or quantum information systems on a diamond chip.
Abstract: Diamond is a promising platform for sensing and quantum processing owing to the remarkable properties of the nitrogen-vacancy (NV) impurity. The electrons of the NV center, largely localized at the vacancy site, combine to form a spin triplet, which can be polarized with 532 nm laser light, even at room temperature. The NV’s states are isolated from environmental perturbations making their spin coherence comparable to trapped ions. An important breakthrough would be in connecting, using waveguides, multiple diamond NVs together optically. However, still lacking is an efficient photonic fabrication method for diamond akin to the photolithographic methods that have revolutionized silicon photonics. Here, we report the first demonstration of three dimensional buried optical waveguides in diamond, inscribed by focused femtosecond high repetition rate laser pulses. Within the waveguides, high quality NV properties are observed, making them promising for integrated magnetometer or quantum information systems on a diamond chip.
TL;DR: In this article, an experimental breakthrough in coupling nitrogen vacancy centers strongly to acoustic waves in a way that still preserves their spin coherence is reported, which may be key in future quantum information processing efforts.
Abstract: Coupling artificial atoms and acoustic waves may be key in future quantum information processing efforts. An experimental breakthrough in coupling nitrogen vacancy centers strongly to acoustic waves in a way that still preserves their spin coherence is reported.
TL;DR: A microwave planar ring antenna specifically designed for optically detected magnetic resonance (ODMR) of nitrogen-vacancy (NV) centers in diamond, ensuring that ODMR can be observed under external magnetic fields up to 100 G without the need of adjustment of the resonance frequency.
Abstract: We report on a microwave planar ring antenna specifically designed for optically detected magnetic resonance (ODMR) of nitrogen-vacancy (NV) centers in diamond. It has the resonance frequency at around 2.87 GHz with the bandwidth of 400 MHz, ensuring that ODMR can be observed under external magnetic fields up to 100 G without the need of adjustment of the resonance frequency. It is also spatially uniform within the 1-mm-diameter center hole, enabling the magnetic-field imaging in the wide spatial range. These features facilitate the experiments on quantum sensing and imaging using NV centers at room temperature.
TL;DR: In this paper, a thermally conducting composite material that can be rapidly 3D printed into prototype objects is presented using a low-cost stereolithographic 3D printer, where the composite structures containing 10, 20, 25 and 30% (w/v) of 2-4 micron sized synthetic diamond microparticles added to the acrylate polymer were produced using a high resolution scanning electron microscopy, thermogravimetric analysis and thermal imaging.
Abstract: The development of a thermally conducting composite material that can be rapidly 3D printed into prototype objects is presented. The composite structures containing 10, 20, 25 and 30% (w/v) of 2–4 micron sized synthetic diamond microparticles added to the acrylate polymer were produced using a low cost stereolithographic 3D printer. The prepared materials were characterised according to heat transfer rates, thermal expansion co-efficients and contact angles, and analysed using high resolution electron microscopy, thermogravimetric analysis and thermal imaging. The composites displayed minor enhancements in heat transfer rates with incrementing diamond content upto 25% (w/v), however a significant improvement was observed for the 30% (w/v) polymer–diamond composite, based on an interconnected diamond aggregate network, as confirmed by high resolution scanning electron microscopy. The developed material was used in the fabrication of prototype 3D printed heat sinks and cooling coils for thermal management applications in electronic and fluidic devices. Infrared thermal imaging performed on 3D printed objects verified the superior performance of the composite compared to the inherent polymer.
TL;DR: In this paper, the authors demonstrate on-chip diamond nanophotonics with a high efficiency fiber-optical interface, achieving > 90% power coupling at visible wavelengths, and demonstrate a bright source of narrowband single photons based on a silicon-vacancy color center embedded within a waveguide-coupled diamond photonic crystal cavity.
Abstract: Color centers in diamond provide a promising platform for quantum optics in the solid state, with coherent optical transitions and long-lived electron and nuclear spins. Building upon recent demonstrations of nanophotonic waveguides and optical cavities in single-crystal diamond, we now demonstrate on-chip diamond nanophotonics with a high efficiency fiber-optical interface, achieving > 90% power coupling at visible wavelengths. We use this approach to demonstrate a bright source of narrowband single photons, based on a silicon-vacancy color center embedded within a waveguide-coupled diamond photonic crystal cavity. Our fiber-coupled diamond quantum nanophotonic interface results in a high flux of coherent single photons into a single mode fiber, enabling new possibilities for realizing quantum networks that interface multiple emitters, both on-chip and separated by long distances.
20 Sep 2016
TL;DR: In this paper, a single-crystal diamond cavity optomechanical device that can enable photon-phonon spin coupling to 2 GHz frequency has been demonstrated, which can enable new ways for photons to control solid-state qubits.
Abstract: Single-crystal diamond cavity optomechanical devices are a promising example of a hybrid quantum system: by coupling mechanical resonances to both light and electron spins, they can enable new ways for photons to control solid-state qubits. However, realizing cavity optomechanical devices from high-quality diamond chips has been an outstanding challenge. Here, we demonstrate single-crystal diamond cavity optomechanical devices that can enable photon–phonon spin coupling. Cavity optomechanical coupling to 2 GHz frequency (
TL;DR: In this article, the authors studied the thermal conduction in suspended polycrystalline diamond films, with thickness ranges between 0.5 and 5.6 μm, using time-domain thermoreflectance.
Abstract: While there is a great wealth of data for thermal transport in synthetic diamond, there remains much to be learned about the impacts of grain structure and associated defects and impurities within a few microns of the nucleation region in films grown using chemical vapor deposition. Measurements of the inhomogeneous and anisotropic thermal conductivity in films thinner than 10 μm have previously been complicated by the presence of the substrate thermal boundary resistance. Here, we study thermal conduction in suspended films of polycrystalline diamond, with thicknesses ranging between 0.5 and 5.6 μm, using time-domain thermoreflectance. Measurements on both sides of the films facilitate extraction of the thickness-dependent in-plane ( κr) and through-plane ( κz) thermal conductivities in the vicinity of the coalescence and high-quality regions. The columnar grain structure makes the conductivity highly anisotropic, with κz being nearly three to five times as large as κr, a contrast higher than that report...
TL;DR: In this article, the in-plane thermal conductivity of polycrystalline diamond near its nucleation site, which is a key parameter to an efficient integration of diamond in modern high power AlGaN/GaN high electron mobility devices, has been studied.
TL;DR: A novel co-reactant-free electrogenerated chemiluminescence (ECL) system is developed where Ru(bpy)32+ emission is obtained on boron-doped diamond (BDD) electrodes and the intensity of the emitted signal increases linearly with [SO42-] up to ∼0.6 M.
Abstract: A novel co-reactant-free electrogenerated chemiluminescence (ECL) system is developed where Ru(bpy)32+ emission is obtained on boron-doped diamond (BDD) electrodes. The method exploits the unique ability of BDD to operate at very high oxidation potential in aqueous solutions and to promote the conversion of inert SO42– into the reactive co-reactant S2O82–. This novel procedure is rather straightforward, not requiring any particular electrode geometry, and since the co-reactant is only generated in situ, the interference with biological samples is minimized. The underlying mechanism is similar to that of the Ru(bpy)32+/S2O82– system; however, the intensity of the emitted signal increases linearly with [SO42–] up to ∼0.6 M, with possible implications for analytical uses of the proposed procedure.
TL;DR: High-resolution magnetic field imaging with a scanning fiber-optic probe which couples nitrogen-vacancy centers in diamond to a high-numerical-aperture photonic-crystal fiber integrated with a two-wire microwave transmission line is demonstrated.
Abstract: We demonstrate high-resolution magnetic field imaging with a scanning fiber-optic probe which couples nitrogen-vacancy (NV) centers in diamond to a high-numerical-aperture photonic-crystal fiber integrated with a two-wire microwave transmission line. Magnetic resonance excitation of NV centers driven by the microwave field is read out through optical interrogation through the photonic-crystal fiber to enable high-speed, high-sensitivity magnetic field imaging with sub 30 μm spatial resolution.