Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers

We demonstrate a new approach for engineering group IV semiconductor-based quantum photonic structures containing negatively charged silicon-vacancy (SiV$^-$) color centers in diamond as quantum emitters. Hybrid SiC/diamond structures are realized by combining the growth of nanoand micro-diamonds on silicon carbide (3C or 4H polytype) substrates, with the subsequent use of these diamond crystals as a hard mask for pattern transfer. SiV$^-$ color centers are incorporated in diamond during its synthesis from molecular diamond seeds (diamondoids), with no need for ionimplantation or annealing. We show that the same growth technique can be used to grow a diamond layer controllably doped with SiV$^-$ on top of a high purity bulk diamond, in which we subsequently fabricate nanopillar arrays containing high quality SiV$^-$ centers. Scanning confocal photoluminescence measurements reveal optically active SiV$^-$ lines both at room temperature and low temperature (5 K) from all fabricated structures, and, in particular, very narrow linewidths and small inhomogeneous broadening of SiV$^-$ lines from all-diamond nano-pillar arrays, which is a critical requirement for quantum computation. At low temperatures (5 K) we observe in these structures the signature typical of SiV$^-$ centers in bulk diamond, consistent with a double lambda. These results indicate that high quality color centers can be incorporated into nanophotonic structures synthetically with properties equivalent to those in bulk diamond, thereby opening opportunities for applications in classical and quantum information processing

Everybody’s Publishing but Me! How a Writing Group Can Help Actualize Your Publishing Dreams

On any given day, one can go to the Chronicle of Higher Education and see a new article on the trials and tribulations of publishing and seeking tenure in academia. Anxiety inducing titles such as “Measuring Up” and “The Stress of Academic Publishing” reaffirm the notion that one must publish, or perish. While this type of pressure pushes some to success, for others, it makes it harder to write. However, you don’t have to travel this writing and publishing road alone. Inspired by the book Every Other Thursday: Stories and Strategies from Successful Women Scientists by Ellen Daniell, a small group of women academics and professionals in Logan, Utah found their support team through the creation of a writing group in Spring 2009

RELATIONSHIP OF SERUM DIPEPTIDYL PEPTIDASE-IV ACTIVITY AND ANTI-CASEIN ANTIBODIES TO GASTROINTESTINAL SYMPTOMS AMONG CHILDREN WITH AUTISM SPECTRUM DISORDER: AN EGYPTIAN STUDY

 Objectives: The objectives of the study were to assess serum dipeptidyl peptidase-IV (DPP-IV) activity in autistic children suffering from severe gastrointestinal (GI) disorder and to examine the hypothesis that there is a link between DPP-IV activity in serum and GI disorder in a subgroup of children with autism spectrum disorder (ASD).Subjects and Methods: Serum levels of casein antibodies and DPP-IV enzyme activity from 40 autistic children with chronic GI symptoms, and 40 of age-matched children without autism or gastrointestinal (GI) symptoms were assayed using enzyme-linked immunosorbent assay kits.Results: In comparison with controls, developmental milestones were delayed among autistic children. The serum DPP-IV activity was significantly lower in the studied patients (p<0.05), while the mean serum levels of casein antibodies were statistically significantly higher in the studied patients (p<0.01). Multiple logistic regression analysis recorded significant association between the high serum level of antibodies to casein, food selectivity and recurrent attacks of abdominal pain (p<0.05), while the low serum DPP-IV enzyme activity was associated with recurrent attacks of abdominal pain in the studied patients with a prediction of 95% (p<0.05).Conclusions: Serum levels of casein antibodies were higher in children with ASD, and maybe contributes to their abdominal pain, and food selectivity. Serum DPP-IV enzyme activity was lower and associated with recurrent attacks of abdominal pain in the studied patients. They may benefit from a supplemental digestive enzyme formula

Inverse plasma equilibria

We illustrate in some detail a 2D inverse-equilibrium solver that was constructed to analyze tokamak configurations and stellarators (the latter in the context of the average method). To ensure that the method is suitable not only to determine equilibria, but also to provide appropriately represented data for existing stability codes, it is important to be able to control the Jacobian, tilde J is identical to delta(R,Z)/delta(rho, theta). The form chosen is tilde J = J/sub 0/(rho)R/sup l/rho where rho is a flux surface label, and l is an integer. The initial implementation is for a fixed conducting-wall boundary, but the technique can be extended to a free-boundary model

Frequency-resolved Monte Carlo

We adapt the Quantum Monte Carlo method to the cascaded formalism of quantum optics, allowing us to simulate the emission of photons of known energy. Statistical processing of the photon clicks thus collected agrees with the theory of frequency-resolved photon correlations, extending the range of applications based on correlations of photons of prescribed energy, in particular those of a photon-counting character. We apply the technique to autocorrelations of photon streams from a two-level system under coherent and incoherent pumping, including the Mollow triplet regime where we demonstrate the direct manifestation of leapfrog processes in producing an increased rate of two-photon emission events