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The problem of the coherent control of atomic states, preparation of atoms in a stable superposition state, and atomic population transfer has attracted much attention in the last decade. One of the main motivations is associated with the rapid development of the field of quantum computing. One of the key problems of quantum information processing is the construction of given coherent superposition atomic states in a macroscopic volume. Stimulated Raman adiabatic passage (STIRAP) [1] is considered to be the most common method for atomic population transfer in quantum systems. Being analyzed in detail on various quantum systems from both theoretical and experimental points of view, this method is widely adopted for the implementation of tools as optical devices for atomic beams, control of chemical reactions, high-precision magnetometry, atom cooling, etc. Meanwhile, an alternative method for population transfer, based on the intuitive pulse sequence with large one-photon detunings was demonstrated in [2]. In contrast with the STIRAP method, where the population transfer is realized via a dark state, the population transfer for the intuitive pulse sequence is obtained via a bright state. The authors of [2] called the atomic population transfer of this kind b-STIRAP. A detailed theoretical analysis of the b-STIRAP process in media with equal oscillator strength on adjacent transitions was performed in [3]. However, it is well-known that an oscillator strengths ratio different from unity can considerably impact on the coherent processes in Λ-media (see e.g. [4]). In the present work an analytical and numerical analysis of the b-STIRAP process in a medium with unequal oscillator strengths is performed. It is shown that the length of population transfer can be considerably increased by an appropriate choice of the dipole transitions. 1. N.V.Vitanov, B.W.Shore,K.Bergman, Adv. Atom.,Mol, Optical Physics, 46, 55-190, (2001). 2. J.Klein, F.Beil, Th.Halfmann, , Phys.Rev.Lett. 99,113003 (2007) 3. G.G. Grigoryan, G. Nikoghosyan, T. Halfmann, Y.T. Pashayan-Leroy, C. Leroy, S.Guerin, Phys.Rev. A 80, 033402 (2009) 4. G.G.Grigoryan, Y.Pashayan, Propagation of pulses in a three-level medium at exact two-photon resonance. Phys.Rev. A 64, 013816, 2001

In this chapter, we focus on the key areas in which further policy action is needed in Turkey's telecommunications sector, assessing the current state-of-play and paying close attention to the ongoing negotiations with the EU in the context of Chapter 10, on information society and media, which was opened in late 2008.

The phase change technology behind rewritable optical disks and the latest generation of electronic memories has provided clear commercial and technological advances for the field of data storage, by virtue of the many well known attributes, in particular scaling, cycling endurance and speed, that chalcogenide materials offer. While the switching power and current consumption of established germanium antimony telluride based memory cells are a major factor in chip design in real world applications, often the thermal stability of the device can be a major obstacle in the path to the full commercialisation. In this work we describe our research in material discovery and characterization for the purpose of identifying more thermally stable chalcogenides for applications in PCRAM.

National audience; Le sujet présenté s'appuie sur une étude réalisée dans le cadre d'un contrat de rivière. Il concerne la définition d'un observatoire des effets des actions menées pour améliorer et préserver la qualité des cours d'eau d'un bassin périurbain soumis à un développement urbain soutenu. La définition de l'observatoire est avant tout le fruit d'un partenariat de plusieurs années entre scientifiques et la structure porteuse du contrat qui regroupe les collectivités concernées. Les scientifiques apportent la vision de synthèse du fonctionnement du cours d'eau à partir des nombreuses études techniques réalisées dans le cadre du contrat et des études scientifiques réalisées en parallèle au travers d'une convention d'appuis scientifique. Le contrat met en retour à disposition l'ensemble des données des études qu'il a financées.

We show that the phase-change technology behind rewritable optical disks and the latest generation of electronic memories can also offer applications in active plasmonics and metamaterials. A range of chalcogenides have been fabricated and characterized for their optical, thermal and electrical properties. Experimental demonstrations show that excitation-induced refractive index changes in gallium lanthanum sulphide (Ga:La:S), a can provide high contrast switching functionality. We have fabricated a silver/GLS interface which can support surface plasmon-polaritons and also incorporated a Ga:La:S thin film with a metamaterials based on arrays of resonance cells. We demonstrate both plasmonic modulation and metamaterials switching through reversible refractive index changes in the chalcogenide.

International audience; The propagation of two optical pulses in a non-linear -type atomic medium is considered. The analytical solution to the self-consistent Maxwell-Schrödinger equations in the adiabatic following condition is obtained. Superluminal effects during propagation of pulses in the medium are studied.

The efficacy of anti-tumour necrosis factor-alpha (TNF-alpha) therapies in rheumatoid arthritis (RA) has been mainly attributed to TNF-alpha neutralisation. Other mechanism as immune cell apoptosis, which is impaired in RA, may also be induced by anti-TNF-alpha therapies. The aim of our study was to investigate whether TNF-alpha inhibitors could induce apoptosis in vitro of the peripheral blood lymphocytes of RA patients.Peripheral blood mononuclear cells (PBMC) isolated from 24 patients with RA and 18 healthy donors were incubated with anti-TNF-alpha agents, infliximab or etanercept, in comparison with no agent and including an isotypic control, for 48 hours. Apoptosis was detected and quantified by annexin V labelling of phosphatidylserine externalization using cytofluorometric analysis and compared with PBMC production TNF-alpha in vitro.In healthy donors, induced apoptosis was observed in 0.3% to 3.8% of lymphocytes with both therapies. In RA patients the treatment induced lymphocyte apoptosis in 17 of 24 patients with a percentage of annexin V-positive lymphocytes ranging from 0.1% to 25%. Among these 17 RA patients, a significant in vitro lymphocyte apoptosis (4%) was observed in 11 patients (46%) compared with healthy donors (p0.01). The variability of the response to anti-TNF-alpha within the RA population was not dependent on TNF-alpha synthesis or disease activity.In vitro induction of lymphocyte apoptosis by anti-TNF-alpha was observed in a subgroup of RA patients. Based on these data, it would be of interest to further study the interindividual variations of sensitivity to apoptosis induced by TNF alpha inhibitors in relation to treatment efficacy or resistance observed in RA patients.

The electrical, optical and phase change properties of bismuth doped Sb8Te2 as-deposited and re-amorphised films have been characterised. Thin films of the material, with up to 15 atomic percent bismuth, have been synthesised by sputter deposition. As deposited amorphous films were stable at room temperature with a bismuth concentration upto 13 atomic percent. We show that effect of bismuth on the phase change properties of the films is to reduce the crystallization time by an order of magnitude. Both static and dynamic measurements of the as-deposited and reamorphised films have showed similar decreases of crystallisation time with bismuth increases. The crystallisation activation energy reduction appears unaffected by the bismuth atoms up to a concentration of 13 atomic percent. The structure of the films after annealing at 180ºC has been measured by X-ray diffraction; the material shows the same A7-type structure as that previously reported for the well known phase change film Ag3.4In3.7Sb76.4Te16.5. A reduction in the material viscosity with increasing bismuth is suggested as a means by which the reduction in crystallisation time is achieved while a negligible change in activation energy and structure is possible. The effect of bismuth dopants on the Sb8Te2 materialʼs physical properties and the consequent performance of optical media and electrical devices will be discussed.

electronic version (8 pp.); International audience

peer-reviewed Since the opening of a temporary ice-rink in our hospital's catchment area, we have observed an increase in patients requiring in-patient treatment for orthopaedic intervention. The authors performed a prospective analysis of all patients admitted to our unit over a one-month period. Epidemiological data, wearing of protective gear and skater experience were collected. Fracture type, treatment required, average length of hospital stay and number of days missed from work was also recorded. Ice-skating injuries accounted for 7.7% of our total admissions over the study period. There was a significant variation noted in the types of fracture sustained ranging from comminuted fractures of the radial head to spiral fractures of the tibia. The average length of hospital stay was 2.6 days and average time missed from work was 6.1 weeks. This paper highlights the potential serious injuries that can occur in ice-skating and their impact on admissions to our orthopaedic unit.

The ability to store information through the phase change mechanism is a well established technology for optical data storage, with typically germanium antimony telluride based films forming the active layer of a phase change disc. However, the ever increasing need for greater storage densities, shorter write/erase, duration and longer archival time is driving interest beyond these established materials. A new thin high throughput thin film deposition method provides a well controlled route to the synthesis of a wide range of chalcogenide compositions through simultaneous deposition of the component elements. When combined with fast primary and secondary screening techniques, the amorphous / crystalline phase transition can be characterised across the ternary compositional space. When combined with a full high throughput characterisation of the phases using EDX and XRD, conductivity measurements and ellipsometric characterisation of the optical properties, a better understanding of the desired phenomena for phase change memory applications is accessible. Results of a high throughput study of the GeSbTe system are presented.

For more than 15 years researchers at the Optoelectronics Research Centre at the University of Southampton have been developing novel compositions of chalcogenide glasses for a wide range of optical applications. Recently this expertise has been combined with those of Ilika Technologies Ltd and the School of Chemistry to focus on the development of enhanced chalcogenide materials for OUM and optical data storage applications. In our talk, we report on our high throughput methodology which allows rapid, reproducible and comprehensive mapping of phase diagrams and screening of optical, thermal and electrical properties. These procedures were initially applied to Ge:Sb:Te compositions where we were able to synthesis and analyse over 4000 sample points spanning the entire ternary system. In order to process such large volumes of compositions, novel screening techniques and strategies have been employed. We are applying this methodology to other novel compositions and our findings are reported.

International audience

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