Atom-Resonant Heralded Single Photons by Interaction-Free Measurement

We demonstrate the generation of rubidium-resonant heralded single photons for quantum memories. Photon pairs are created by cavity-enhanced down-conversion and narrowed in bandwidth to 7 MHz with a novel atom-based filter operating by "interaction-free measurement" principles. At least 94% of the heralded photons are atom-resonant as demonstrated by a direct absorption measurement with rubidium vapor. A heralded auto-correlation measurement shows $g_c^{(2)}(0)=0.040 \pm 0.012$, i.e., suppression of multi-photon contributions by a factor of 25 relative to a coherent state. The generated heralded photons can readily be used in quantum memories and quantum networks.Comment: 5 pages, 4 figure

Decoy States and Two Way Quantum Key Distribution Schemes

We study the possible application of the decoy state method on a basic two way quantum key distribution (QKD) scheme to extend its distance. Noting the obvious advantage of such a QKD scheme in allowing for single as well as double photon contributions, we derive relevant lower-bounds on the corresponding gains in a practical decoy state implementation using two intensities for decoy states. We work with two different approaches in this vein and compare these with an ideal infinite decoy state case as well as the simulation of the original.Comment: Much revised from original manuscript. Accepted for publication in Optics Communications (some variations may exist in some wordings in the text

Elaboration and characterization of the electrodeposited phosphates masses doped with various ions on stainless steel

The present paper is focused on elaboration of phosphate masses with good molar ratios on SS 316L, with fluoride, Zn2+ and Cu2+ as dopant ions, using an electrochemical procedure and also the attempt to select the best conditions for stainless steel. The surface was characterized using X-ray difraction, AFM and contact angle measurements. X-ray has evidenced crystaline phases, contact angle measurements has established the balance hydrophyl-hydrophob and AFM established roughness values. The inductively coupled spectrometry (ICP-MS) has quantified the amount of cooper and zinc ions released. In order to be used in biomedical applications hemolysis and antibacterial tests have been performed.Fil: Totea, G.. Faculty of Applied Chemistry and Materials Science; RumaniaFil: Ionita, D.. Faculty of Applied Chemistry and Materials Science; RumaniaFil: Katunar, Maria Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Cere, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Demetrescu, I.. Faculty of Applied Chemistry and Materials Science; Rumani

Experimental Study of the Quantum States of Light and Realization of a Quantum Communication Protocol\ud

I present how to obtain and characterize quantum states of light potentially useful for quantum communication protocols. The control of the frequency correlations,\ud and the bandwidth, of single and paired photons is an essential ingredient in specific quantum applications, from quantum imaging to quantum clock synchronization.\ud I show both theoretical and experimental spectral correlations of pairs of photons generated in non-collinear spontaneous parametric down conversion (SPDC). In the second part of the work, a scheme for quantum key distribution using the two-way LM05 protocol [PRL 94, 140501 (2005)] and its implementation is presented too. A preliminary transmission test is discussed together with\ud an experimental study for the security of the generated key in presence of noise in the channels. The noise is modulated as to simulate the effect of an eavesdropper.\u

Structure and dielectric properties of electrochemically grown ZrO2 films

The dielectric properties of electrochemically grown zirconium oxide films by anodisation of zirconium in 1.0 mol dm?3 phosphoric acid solution were investigated in a 3 to 30 V potential range with a view to inducing surface modifications for eventual use in biomedical and electronic applications. The oxide films grown at different potentials were characterised by Atomic Force Microscopy, X-ray photoelectron and Raman spectroscopies; the latter demonstrated the incorporation of phosphate ions into the passive films. Flat band potentials calculated from the Mott-Shottky analysis of the oxides semiconducting properties confirm the bilayer structure of the films. The oxide dielectric permittivity was evaluated from impedance spectroscopy measurements and the film oxide model proposed gave values independent of the oxide growth potentialFil: Gomez Sanchez, Andrea Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Katunar, Maria Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Schreiner, Wido. Universidade Federal do Paraná. Departamento de Física; BrasilFil: Duffo, Gustavo Sergio. Comision Nacional de Energia Atomica. Gerencia D/area de Energia Nuclear. Unidad de Actividad de Materiales (cac); Argentina. Universidad Nacional de San Martín; ArgentinaFil: Cere, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Schiffrin, David. University of Liverpool; Reino Unid

Can anodised zirconium implants stimulate bone formation? Preliminary study in rat model

Mechanical properties and good biocompatibility of zirconium and some of its alloys focus these materials as good candidates for biomedical applications. The attractive in vivo performance of zirconium is mainly due to the presence of a protective oxide layer. In this preliminary study, surface modification of pure zirconium was made by anodisation in acidic media at low potentials, enhancing the barrier protection given by the oxides and the osseointegration. Electrochemical and SEM (scanning electron microscopy) assays were done in commercially pure zirconium cylinders and two surface conditions were compared: pure and zirconium anodised at 30V. The in vivo assays were held in a tibia rat model. The histological features and fluorochrome labelling changes of newly bone formed around implants were evaluated on the non-decalcified sections 63 days after surgery. Electrochemical and SEM assays showed that anodisation treatment would increased the barrier effect over the material and the in vivo assays showed a continuous newly bone formation around the implant with a different amount of osteocytes in their lacunaes depending the region. There was no significant change in bone thickness around both kinds of implants but conversely a significant increase in the mineralization apposition rate was determined for the anodised condition suggesting that anodisation treatment would stimulate and assist to the osseointegration process. We conclude that anodisation treatment at 30 V can stimulate the implant fixation in a rat model and this study would propose the study of zirconium as candidate material for permanent implant.Fil: Katunar, Maria Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Gomez Sanchez, Andrea Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Ballarre, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Baca, Matías. Hospital Interzonal General de Agudos ‘‘Oscar Alende’’. Mar del Plata; ArgentinaFil: Vottola, Carlos. Hospital Interzonal General de Agudos ‘‘Oscar Alende’’; ArgentinaFil: Orellano, Juan C.. Hospital Interzonal General de Agudos ‘‘Oscar Alende’’. Mar del Plata; ArgentinaFil: Schell, Hanna. Universitatsmedizin Berlin; AlemaniaFil: Duffo, Gustavo Sergio. Comision Nacional de Energia Atomica. Gerencia D/area de Energia Nuclear. Unidad de Actividad de Materiales (cac); Argentina. Universidad Nacional de San Martín; ArgentinaFil: Cere, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentin

Independent Attacks in Imperfect Settings; A Case for A Two Way Quantum Key Distribution Scheme

We review the study on a two way quantum key distribution protocol given imperfect settings through a simple analysis of a toy model and show that it can outperform a BB84 setup. We provide the sufficient condition for this as a ratio of optimal intensities for the protocols

Foreign Language Careers for International Business and the Professions

The U.S. work and market places are becoming more global, multilingual, and multicultural in nature and are making foreign language and cultural studies, particularly those of Asia and Latin America, an important part of career planning and development. Many jobs demand knowledge of one or more languages and their attendant cultures and require experience in international and/or cross cultural areas. They also demand specialized interdisciplinary training such as that offered at many schools, colleges, and universities, and encourage internships that can lead to promising careers. Job sources for foreign language-based careers also abound and with guidance and research can be easily found. This paper seeks to provide the information and sources educators at all levels and institutions need to know in order to emphasize the importance of foreign language in careers and also facilitate ways of integrating their study into the general curriculum and classroom