86 research outputs found
Optical Line Width Broadening Mechanisms at the 10 kHz Level in Eu3+:Y2O3 Nanoparticles
We identify the physical mechanisms responsible for the optical homogeneous broadening in Eu3+:Y2O3 nanoparticles to determine whether rare-earth crystals can be miniaturized to volumes less than λ3 whilst preserving their appeal for quantum technology hardware. By studying how the homogeneous line width depends on temperature, applied magnetic field, and measurement time scale the dominant broadening interactions for various temperature ranges above 3 K were characterized. Below 3 K the homogeneous line width is dominated by an interaction not observed in bulk crystal studies. These measurements demonstrate that broadening due to size-dependent phonon interactions is not a significant contributor to the homogeneous line width, which contrasts previous studies in rare-earth ion nanocrystals. Importantly, the results provide strong evidence that for the 400 nm diameter nanoparticles under study the minimum line width achieved (45±1 kHz at 1.3 K) is not fundamentally limited. In addition, we highlight that the expected broadening caused by electric field fluctuations arising from surface charges is comparable to the observed broadening. Under the assumption that such Stark broadening is a significant contribution to the homogeneous line width, several strategies for reducing this line width to below 10 kHz are discussed. Furthermore, it is demonstrated that the Eu3+ hyperfine state lifetime is sufficiently long to preserve spectral features for timescales up to 1 s. These results allow integrated rare-earth ion quantum optics to be pursued at a sub-micron scale and hence, open up directions for greater scaling of rare-earth quantum technology
Narrow Optical and Spin Linewidths in Rare-earth Doped Micro- and Nano-structures
This invited presentation was given at the 47th conference on the Physics of Quantum Electronics, which took place in Snowbird, USA from January 8 to 13, 2017. It gives an overview of the current developments on rare earth doped nanoparticles and transparent ceramics spectroscopy at Chimie ParisTech
Narrow inhomogeneous and homogeneous optical linewidths in a rare earth doped transparent ceramic
Inhomogeneous and homogeneous linewidth are reported in a Eu3+ doped transparent Y2O3 ceramic for the 7F 0-5D0 transition, using high-resolution coherent spectroscopy. The 8.7-GHz inhomogeneous linewidth is close to that of single crystals, as is the 59-kHz homogeneous linewidth at 3 K (T2 = 5.4 μs). The homogeneous linewidth exhibits a temperature dependence that is typical of a crystalline environment, and additional dephasing observed in the ceramic is attributed to magnetic impurities or defects introduced during the synthesis process. The absence of Eu3+segregation at the grain boundaries, evidenced through confocal microfluorescence, further indicates that the majority of Eu3+ions in the ceramic experience an environment comparable to a single crystal. The obtained results suggest that ceramic materials can be competitive with single crystals for applications in quantum information and spectral hole burning devices, beyond their current applications in lasers and scintillatorsThis work was supported by National Science Foundation under award No. PHY-1212462, the European Union FP7 project QuRep (247743), the Spanish Ministry of Economy
and Competitiveness (MAT2010-17443) and Comunidad de Madrid (S-2009/MAT-1756
Emission of photon echoes in a strongly scattering medium
We observe the two- and three-pulse photon echo emission from a scattering
powder, obtained by grinding a Pr:YSiO rare earth doped single
crystal. We show that the collective emission is coherently constructed over
several grains. A well defined atomic coherence can therefore be created
between randomly placed particles. Observation of photon echo on powders as
opposed to bulk materials opens the way to faster material development. More
generally, time-domain resonant four-wave mixing offers an attractive approach
to investigate coherent propagation in scattering media
Local environment of optically active Nd3 + ions in the ultratransparent BaMgF 4 ferroelectric crystal
A comprehensive study of the site location of Nd3 + ions in the BaMgF 4 ultratransparent ferroelectric crystal is presented. By combining different low-temperature optical spectroscopies and electron paramagnetic resonance, the crystal field energy levels of Nd3 + ions and the gyromagnetic factors are experimentally determined. These results are employed to perform the crystal field analysis of Nd3 + ions considering a Cs point symmetry. The crystal field calculation yields a small root-mean-square deviation of 18 cm -1 and reveals a large crystal field strength (621 cm -1), verifying the assignment of the Ba2 + cationic site as the location for Nd3 + ions in this fluoride host. The results suggest a slight displacement of Nd3 + from the barium regular site with a rearrangement of the fluorine ions around it. The work gives a deep insight into the properties of the Nd3 +-doped BaMgF 4 crystal, a ferroelectric widely ultra-transparent material with potential applications as optical device operating in the Vacuum Ultraviolet-Ultraviolet and midinfrared spectral regionsThis work has been supported by the Spanish Ministry of Science under projects MAT2010-17443, MAT2010-21270-C04-02, Consolider-Ingenio MALTA CSD 2007-0045, and Comunidad Autonoma de Madrid under Grant 2009/MAT-175
Effects of Hydrogen Peroxide on Wound Healing in Mice in Relation to Oxidative Damage
10.1371/journal.pone.0049215PLoS ONE711
A Measurement of the Proton Structure Function
A measurement of the proton structure function is reported
for momentum transfer squared between 4.5 and 1600 and
for Bjorken between and 0.13 using data collected by the
HERA experiment H1 in 1993. It is observed that increases
significantly with decreasing , confirming our previous measurement made
with one tenth of the data available in this analysis. The dependence is
approximately logarithmic over the full kinematic range covered. The subsample
of deep inelastic events with a large pseudo-rapidity gap in the hadronic
energy flow close to the proton remnant is used to measure the "diffractive"
contribution to .Comment: 32 pages, ps, appended as compressed, uuencoded fil
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