A5020134074- Diamond and Carbon-based Materials Research
- Semiconductor Quantum Structures and Devices
- Quantum Information and Cryptography
- High-pressure geophysics and materials
- Advanced Fiber Laser Technologies
- Photonic and Optical Devices
- Carbon Nanotubes in Composites
- Mechanical and Optical Resonators
- Semiconductor Lasers and Optical Devices
- Quantum Computing Algorithms and Architecture
- Semiconductor materials and devices
- Advanced materials and composites
- Metal and Thin Film Mechanics
- Quantum Mechanics and Applications
- Tunneling and Rock Mechanics
- Quantum and electron transport phenomena
- Advanced Surface Polishing Techniques
- Force Microscopy Techniques and Applications
- Atomic and Subatomic Physics Research
- Nonlinear Optical Materials Studies
- Quantum Dots Synthesis And Properties
- Strong Light-Matter Interactions
- GaN-based semiconductor devices and materials
- Catalytic Processes in Materials Science
- Fullerene Chemistry and Applications
Stockholm University
2020-2025
Cardiff University
2016-2022
University of Würzburg
2020
Consejo Superior de Investigaciones Científicas
2013
In this paper, the origin of positive zeta potential exhibited by nanodiamond particles is explained. Positive potentials in nano-structured carbons can be explained presence graphitic planes at surface, which leave oxygen-free Lewis sites and so promotes suppression acidic functional groups. Electron Microscopy Raman Spectroscopy have been used to show that only sp2 carbon surface.
The silicon-vacancy (SiV) color center in diamond is a solid-state single photon emitter and spin quantum bit suited as component devices. Here, we show that the SiV nanodiamond exhibits strongly inhomogeneous distribution with regard to wavelengths linewidths of zero-phonon-line (ZPL) emission at room temperature. We find centers separate two clusters: one group ZPLs within narrow range approximatly 730 nm 742 broad between 5 17 nm, whereas second comprises very 715 835 but from below 1 up...
Nanodiamonds containing negatively charged nitrogen vacancy centers (${\text{NV}}^{\ensuremath{-}}$) have applications as localized sensors in biological materials and been proposed a platform to probe the macroscopic limits of spatial superposition quantum nature gravity. A key requirement for these is obtain nanodiamonds ${\text{NV}}^{\ensuremath{-}}$ with long spin coherence times. Using milling fabricate processes full 3D volume bulk material at once, unlike etching pillars, but has, up...
The quantification of the entanglement present in a physical system is paramount importance for fundamental research and many cutting-edge applications. Now, achieving this goal requires either priori knowledge on or very demanding experimental procedures such as full state tomography collective measurements. Here, we demonstrate that, by using neural networks, can quantify degree without need to know description quantum state. Our method allows direct correlations an incomplete set local...
Levitated nanodiamonds containing nitrogen vacancy centres in high vacuum are a potential test bed for numerous phenomena fundamental physics. However, experiments so far have been limited to low due heating arising from optical absorption of the trapping laser. We show that milling pure diamond creates do not heat up as intensity is raised above 700 GW/m$^2$ below 5 mbar pressure. This advance now means level attainable dipole traps no longer temperature limited.
The generation of photon pairs in single quantum dots is based on a process that is, its nature, deterministic. However, an efficient extraction these from high-index semiconductor host material requires engineering the photonic environment. We report micropillar-based device featuring efficiency 69.4(10)$\%$ achieved by harnessing broadband operation suitable for emitted dot. Opposing approaches rely solely Purcell enhancement to realize efficiency, our solution exploits suppression...
Color centers are promising single-photon emitters owing to their operation at room temperature and high photostability. In particular, using nanodiamonds as a host material is of interest for sensing metrology. Furthermore, being solid-state system allows incorporation photonic systems tune both the emission intensity photoluminescence (PL) spectrum therefore adapt individual color center desired properties. We show successful coupling single nanodiamond hosting silicon-vacancy plasmonic...
Color centers are promising single-photon emitters owing to their operation at room temperature and high photostability. In particular, using nanodiamonds as a host material is of interest for sensing metrology. Furthermore, being solid-state system allows incorporation photonic systems tune both the emission intensity photoluminescence spectrum therefore adapt individual color center desired properties. We show successful coupling single nanodiamond hosting silicon-vacancy plasmonic double...
A method to observe individual fluorescent crystal defects in nanodiamonds is reported and opens new nanosensing avenues ( e.g. pH nanosensing).
The measurement of ζ potential Ga-face and N-face gallium nitride has been carried out as a function pH. Both the faces show negative in pH range 5.5-9. an isoelectric point at 5.5. shows more due to larger concentration adsorbed oxygen. data clearly showed that H-terminated diamond seed solution 8 will be optimal for self-assembly monolayer nanoparticles on GaN surface. subsequent growth thin films seeded with seeds produced fully coalesced films, confirming seeding density excess 1011...
We introduce a scalable photonic platform that enables efficient generation of entangled photon pairs from semiconductor quantum dot. Our system, which is based on self-aligned dot-micro-cavity structure, erases the need for complex steps lithography and nanofabrication. experimentally show collection efficiency 0.17 combined with Purcell enhancement up to 1.7 in pair emission process. harness potential our device generate time bin, reaching fidelity 0.84(5) maximally state. The achieved 4...
In this paper, the controlled production of high-quality metal-free diamond nanoparticles is demonstrated. Milling with tempered steel shown to leave behind iron oxide contamination which difficult remove. SiN alleviates issue but generates more nondiamond carbon. Thus, choice milling materials critically determined by acceptable contaminants in ultimate application. The removal metal impurities, present all commercially available nanoparticles, will open new possibilities toward customized...
The quantification of the entanglement present in a physical system is para\-mount importance for fundamental research and many cutting-edge applications. Currently, achieving this goal requires either priori knowledge on or very demanding experimental procedures such as full state tomography collective measurements. Here, we demonstrate that by employing neural networks can quantify degree without needing to know description quantum state. Our method allows direct correlations using an...
Excitons in quantum dots are excellent sources of polarization-entangled photon pairs, but a quantitative understanding their interaction with the nuclear spin bath is still missing. Here we investigate role hyperfine energy shifts using experimentally accessible parameters and derive an upper limit to achievable entanglement fidelity. Our results consistent all available literature, indicate that noise often dominant process limiting InGaAs dots, suggest routes alleviate its effect.
In this paper the design of a simple, space constrained chemical vapour deposition reactor for diamond growth is detailed. Based on by NIRIM, composed quartz discharge tube placed within 2.45 GHz waveguide to create conditions required metastable diamond. Utilising largely off-the-shelf components and modular design, allows easy modification, repair, cleaning between runs. The elements are laid out with CAD files, parts list, control files made easily available enable replication. Finally,...
Nanodiamond synthesized by the detonation method is a composite of sp3/sp2 carbon structures; amorphous and disordered-sp2 carbons populate surface sp3 diamond core lattice. Because production process, various elemental impurities such as N, O, H, so forth are inherent in interstitial sites or (sp2/amorphous) network. Herein, reaction dynamics on ultradisperse (UDD) due to transformation reconstruction during annealing vacuum with temperatures ranging from ambient 800 °C described. In situ...
We consider recent developments on nano-diamond reflectors for slow neutrons, which dramatically improve their efficiency.
Excitons in quantum dots are excellent sources of polarization-entangled photon pairs, but a quantitative understanding their interaction with the nuclear spin bath is still missing. Here we investigate role hyperfine energy shifts using experimentally accessible parameters and derive an upper limit to achievable entanglement fidelity. Our results consistent all available literature, indicate that spin-noise often dominant process limiting InGaAs dots, suggest routes alleviate its effect.