971 research outputs found
Universal quantum gates between nitrogen-vacancy centers in a levitated nanodiamond
We propose a scheme to realize universal quantum gates between
nitrogen-vacancy (NV) centers in an optically trapped nanodiamond, through
uniform magnetic field induced coupling between the NV centers and the
torsional mode of the levitated nanodiamond. The gates are tolerant to the
thermal noise of the torsional mode. By combining the scheme with dynamical
decoupling technology, it is found that the high fidelity quantum gates are
possible for the present experimental conditions. The proposed scheme is useful
for NV-center-based quantum network and distributed quantum computationComment: 7 pages, 6 figure
25-nm diamond crystals hosting single NV color centers sorted by photon-correlation near-field microscopy
Diamond nanocrystals containing highly photoluminescent color centers are
attractive non-classical and near-field light sources. For near-field
applications the size of the nanocrystal is crucial since it defines the
optical resolution. NV (Nitrogen-Vacancy) color centers are efficiently created
by proton irradiation and annealing of a nanodiamond powder. Using near-field
microscopy and photon statistics measurements, we show that nanodiamond with
size down to 25 nm can hold a single NV color center with bright and stable
photoluminescence
Understanding the magnetic resonance spectrum of nitrogen vacancy centers in an ensemble of randomly-oriented nanodiamonds
Nanodiamonds containing nitrogen vacancy (NV-) centers show promise for a
number of emerging applications including targeted in vivo imaging and
generating nuclear spin hyperpolarization for enhanced NMR spectroscopy and
imaging. Here, we develop a detailed understanding of the magnetic resonance
behavior of NV- centers in an ensemble of nanodiamonds with random crystal
orientations. Two-dimensional optically detected magnetic resonance
spectroscopy reveals the distribution of energy levels, spin populations, and
transition probabilities that give rise to a complex spectrum. We identify
overtone transitions that are inherently insensitive to crystal orientation and
give well-defined transition frequencies that access the entire nanodiamond
ensemble. These transitions may be harnessed for high-resolution imaging and
generation of nuclear spin hyperpolarization. The data are well described by
numerical simulations from the zero- to high-field regimes, including the
intermediate regime of maximum complexity. We evaluate the prospects of
nanodiamond ensembles specifically for nuclear hyperpolarization and show that
frequency-swept dynamic nuclear polarization may transfer a large amount of the
NV- center's hyperpolarization to nuclear spins by sweeping over a small region
of its spectrum.Comment: 6 pages, 5 figure
Coupling of a Single Quantum Emitter to End-to-end Aligned Silver Nanowires
We report on the observation of coupling a single nitrogen vacancy (NV)
center in a nanodiamond crystal to a propagating plasmonic mode of silver
nanowires. The nanocrystal is placed either near to the apex of a single silver
nanowire or in the gap between two end-to-end aligned silver nanowires. We
observe an enhancement of the NV-centers' decay rate in both cases as a result
of the coupling to the plasmons. The devices are nano-assembled with a scanning
probe technique. Through simulations, we show that end-to-end aligned silver
nanowires can be used as a controllable splitter for emission from a dipole
emitter.Comment: 5 pages, 4 figure
Nitrogen control in nanodiamond produced by detonation shock-wave-assisted synthesis
Development of efficient production methods of nanodiamond (ND) particles containing substitutional nitrogen and nitrogen-vacancy (NV) complexes remains an important goal in the nanodiamond community. ND synthesized from explosives is generally not among the preferred candidates for imaging applications owing to lack of optically active particles containing NV centers. In this paper, we have systematically studied representative classes of NDs produced by detonation shock wave conversion of different carbon precursor materials, namely, graphite and a graphite/hexogen mixture into ND, as well as ND produced from different combinations of explosives using different cooling methods (wet or dry cooling). We demonstrate that (i) the N content in nanodiamond particles can be controlled through a correct selection of the carbon precursor material (addition of graphite, explosives composition); (ii) particles larger than approximately 20 nm may contain in situ produced optically active NV centers, and (iii) in ND produced from explosives, NV centers are detected only in ND produced by wet synthesis. ND synthesized from a mixture of graphite/explosive contains the largest amount of NV centers formed during synthesis and thus deserves special attention. © 2011 American Chemical Society
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