317 research outputs found
Diamond chemical vapor deposition on optical fibers for fluorescence waveguiding
A technique has been developed for depositing diamond crystals on the
endfaces of optical fibers and capturing the fluorescence generated by
optically active defects in the diamond into the fiber. This letter details the
diamond growth on optical fibers and transmission of fluorescence through the
fiber from the nitrogen-vacancy (N-V) color center in diamond. Control of the
concentration of defects incorporated during the chemical vapor deposition
(CVD) growth process is also demonstrated. These are the first critical steps
in developing a fiber coupled single photon source based on optically active
defect centers in diamond.Comment: 10 pages, 3 figure
Quantum gate for Q switching in monolithic photonic bandgap cavities containing two-level atoms
Photonic bandgap cavities are prime solid-state systems to investigate
light-matter interactions in the strong coupling regime. However, as the cavity
is defined by the geometry of the periodic dielectric pattern, cavity control
in a monolithic structure can be problematic. Thus, either the state coherence
is limited by the read-out channel, or in a high Q cavity, it is nearly
decoupled from the external world, making measurement of the state extremely
challenging. We present here a method for ameliorating these difficulties by
using a coupled cavity arrangement, where one cavity acts as a switch for the
other cavity, tuned by control of the atomic transition.Comment: 6 pages, 5 figures, 1 tabl
Optical and electronic properties of sub-surface conducting layers in diamond created by MeV B-implantation at elevated temperatures
Boron implantation with in-situ dynamic annealing is used to produce highly
conductive sub-surface layers in type IIa (100) diamond plates for the search
of a superconducting phase transition. Here we demonstrate that high-fluence
MeV ion-implantation, at elevated temperatures avoids graphitization and can be
used to achieve doping densities of 6 at.%. In order to quantify the diamond
crystal damage associated with implantation Raman spectroscopy was performed,
demonstrating high temperature annealing recovers the lattice. Additionally,
low-temperature electronic transport measurements show evidence of charge
carrier densities close to the metal-insulator-transition. After electronic
characterization, secondary ion mass spectrometry was performed to map out the
ion profile of the implanted plates. The analysis shows close agreement with
the simulated ion-profile assuming scaling factors that take into account an
average change in diamond density due to device fabrication. Finally, the data
show that boron diffusion is negligible during the high temperature annealing
process.Comment: 22 pages, 6 figures, submitted to JA
Single-photon emitting diode in silicon carbide
Electrically driven single-photon emitting devices have immediate
applications in quantum cryptography, quantum computation and single-photon
metrology. Mature device fabrication protocols and the recent observations of
single defect systems with quantum functionalities make silicon carbide (SiC)
an ideal material to build such devices. Here, we demonstrate the fabrication
of bright single photon emitting diodes. The electrically driven emitters
display fully polarized output, superior photon statistics (with a count rate
of 300 kHz), and stability in both continuous and pulsed modes, all at room
temperature. The atomic origin of the single photon source is proposed. These
results provide a foundation for the large scale integration of single photon
sources into a broad range of applications, such as quantum cryptography or
linear optics quantum computing.Comment: Main: 10 pages, 6 figures. Supplementary Information: 6 pages, 6
figure
Engineering chromium related single photon emitters in single crystal diamond
Color centers in diamond as single photon emitters, are leading candidates
for future quantum devices due to their room temperature operation and
photostability. The recently discovered chromium related centers are
particularly attractive since they possess narrow bandwidth emission and a very
short lifetime. In this paper we investigate the fabrication methodologies to
engineer these centers in monolithic diamond. We show that the emitters can be
successfully fabricated by ion implantation of chromium in conjunction with
oxygen or sulfur. Furthermore, our results indicate that the background
nitrogen concentration is an important parameter, which governs the probability
of success to generate these centers.Comment: 14 pages, 5 figure
Controlled single electron transfer between Si:P dots
We demonstrate electrical control of Si:P double dots in which the potential
is defined by nanoscale phosphorus doped regions. Each dot contains
approximately 600 phosphorus atoms and has a diameter close to 30 nm. On
application of a differential bias across the dots, electron transfer is
observed, using single electron transistors in both dc- and rf-mode as charge
detectors. With the possibility to scale the dots down to few and even single
atoms these results open the way to a new class of precision-doped quantum dots
in silicon.Comment: 3 figures, 3 page
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