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A two-module trapped-ion quantum computer prototype
No full textQuantum information technology has the potential to revolutionise a wide range of research fields and to have a profound impact on society. Today, work towards a universal quantum computer is benefiting from recent breakthroughs in quantum hardware engineering. One of the most promising approaches is based on quantum computing modules that are networked via ion shuttling. The modules make use of microfabricated electrodes that create electric fields to confine ensembles of ion qubits. Combining this modular approach with strong magnetic field gradients and long-wavelength radiation quantum gate technology can significantly improve system scalability. Nevertheless, the realisation and simultaneous integration of all the core characteristics of such modules remains an intrinsically challenging task. This doctoral thesis investigates novel techniques and components critical to the engineering of this architecture. A prototype ion trapping system is constructed for the operation of two microfabricated ion-trap modules, which will enable the execution of key operations for networked quantum logic, i.e. high-fidelity one- and two-qubit gates, and shuttling of ion qubits between both modules to realise a matter-based quantum link. In this scheme, high-fidelity quantum gates require a large magnetic field gradient to be generated at the ion position. To achieve this, novel current-carrying wire structures directly embedded within the ion-trap module were developed. These offer a scalable solution to this challenge. The operation of ion traps at cryogenic temperatures is also desirable to further enhance quantum gate fidelities. A thermal model of the ion trap is presented and a cryogenic cooling system capable of meeting the requirements of a large-scale ion-trap architecture is demonstrated. Finally, the constructed two-module ion-trap apparatus is presented. This provides a viable set-up for the execution of these key operations, paving the way towards the realisation of a universal quantum computer
A two-module trapped-ion quantum computer prototype
No full textQuantum information technology has the potential to revolutionise a wide range of research fields and to have a profound impact on society. Today, work towards a universal quantum computer is benefiting from recent breakthroughs in quantum hardware engineering. One of the most promising approaches is based on quantum computing modules that are networked via ion shuttling. The modules make use of microfabricated electrodes that create electric fields to confine ensembles of ion qubits. Combining this modular approach with strong magnetic field gradients and long-wavelength radiation quantum gate technology can significantly improve system scalability. Nevertheless, the realisation and simultaneous integration of all the core characteristics of such modules remains an intrinsically challenging task. This doctoral thesis investigates novel techniques and components critical to the engineering of this architecture. A prototype ion trapping system is constructed for the operation of two microfabricated ion-trap modules, which will enable the execution of key operations for networked quantum logic, i.e. high-fidelity one- and two-qubit gates, and shuttling of ion qubits between both modules to realise a matter-based quantum link. In this scheme, high-fidelity quantum gates require a large magnetic field gradient to be generated at the ion position. To achieve this, novel current-carrying wire structures directly embedded within the ion-trap module were developed. These offer a scalable solution to this challenge. The operation of ion traps at cryogenic temperatures is also desirable to further enhance quantum gate fidelities. A thermal model of the ion trap is presented and a cryogenic cooling system capable of meeting the requirements of a large-scale ion-trap architecture is demonstrated. Finally, the constructed two-module ion-trap apparatus is presented. This provides a viable set-up for the execution of these key operations, paving the way towards the realisation of a universal quantum computer
L'occupation aurignacienne d'Hui (Beauville, Lot-et-Garonne)
No full textZUSAMMENFASSUNG Die Entdeckung der Aurignac-Fundstätte von Hui im Jahre 1981 füllt eine gro$e kulturelle Lücke in dervorgeschichtlichen Chronologie des Agenais und Bas- Quercy. Die Ausgrabungen (programmierte Rettung- sausgrabungen) , die 1986 auf dieser Lagerstàtte begonnen haben, ermöglichen es, die auf anderen Aurignac-Freilichtaufenthaltsorten hauptsàchlich in Zentralund Osteuropa gefundenen Daten zu vervollstàndigen. Aufier der Presentation der Fundstätte und der ersten Ergebnisse (Stratigraphie, Stein-Industrie, Verbreitungsanalyse, Zusammensetzungen, Herkunft der Rohmaterialen) , werden auch methodologische Fragen behandelt wie : Ausgrabungspolitik, Problematik, Ausarbeitung der Angaben.ABSTRACT The discovery in 1981 of the Aurignacian site ofHui fills an important cultural blank in the prehistoric chronology of the Agenais and Bas-Quercy area. Work (planned rescue excavations) began on this site in 1986 and has added to the information found at other open-air Aurignacian occupation sites, most of which have been discovered in Central and Eastern Europe. In addition to the presentation of the site and the first results (stratigraphy, lithic industry, distribution analysis, reassembly , origins of the raw materials), methodological questions such as excavation policy or data processing are also considered.RESUME La découverte en 1981 du site aurignacien I d'Hui comble une importante lacune culturelle dans la chronologie préhistorique de l'Agenais et du Bas-Quercy. Les travaux (fouilles de sauvetage programmées) débutés dès 1986 sur ce gisement permettent de compléter les données trouvées sur d'autres occupations aurignaciennes de plein air in situ, découvertes essentiellement en Europe centrale et orientale. Outre la présentation du site et des premiers résultats (stratigraphie, industrie lithique, analyses de répartition, remontages, origine des matériaux), sont également abordées des questions méthodologiques : politique de fouille, problématique, traitement des données.Le Brun-Ricalens Foni. L'occupation aurignacienne d'Hui (Beauville, Lot-et-Garonne). In: Bulletin de la Société préhistorique française, tome 87, n°9, 1990. pp. 275-282
La production lamellaire et les armatures lamellaires de l ́aurignacien ancien de la Grotte de Fumane (Monts Lessini, Vénétie)
No full textIn the Aurignacian sequence of the Fumane Cave (Lessini Mts., Veneto region), dated between 34 000 and 32 000 BP, bladelet tools are much more frequent (86 % for the lower levels; 58 % for upper levels) than blade and flake tools. Bladelet and microbladelet blanks were produced by direct organic percussion, starting from carenoid, pyramidal and prismatic unipolar cores. Blanks with subparallel edges and a rectilinear, curved or occasionally twisted profile were selected to prepare the armatures.
The following types of armatures were distinguished:
- points with the cusp on the blank axis obtained by two marginal abrupt retouches, sometimes tending to become deeply abrupt on the apical part. The cusp is nearly always situated on the distal portion of the blank;
- bladelets with alternate or inverse abrupt marginal retouch.
Analysis of use-wear traces suggests that over one-third of the armatures (37 %) were used as weapon points. The others were inserted in the blank in series to form composite instruments for cutting, scraping and singly for incision.Dans la séquence aurignacienne de la Grotte de Fumane (Monts Lessini, Vénétie) datée entre 34 000 et 32 000 bp, l’outillage lamellaire prévaut nettement (86 % pour les niveaux inférieurs, 58 % pour les supérieurs) sur les outils sur lame et éclat.
Les supports lamellaires et microlamellaires sont extraits par percussion tendre organique à partir de nucléus unipolaires de type carénoïde, pyramidal et prismatique. Pour la confection des armatures, ont été sélectionnés préférentiellement des supports aux bords subparallèles avec un profil rectiligne ou courbe, plus rarement torse.
Nous avons pu dégager les types suivants d’armatures : - des pointes avec l’apex sur l’axe du support, obtenues par retouches abruptes marginales sur les deux bords qui tendent parfois à l’abrupte profonde sur la partie apicale. L’apex se trouvant toujours sur la partie distale du support ; - des lamelles aux retouches abruptes marginales ou abruptes et d’orientation alterne ou inverse.
L’analyse des traces d’utilisation suggère que plus d’un tiers des armatures (37 %) était utilisé comme pointes d’arme de jet. Les autres étaient emmanchées en série afin de former des outils d’éléments composites pour des actions de coupe ou de raclage, ou uniquement pour inciser
HiN : Alexander von Humboldt im Netz
No full text-Ingo Schwarz, Vera M. Kutzinski: A Letter from Alexander von Humboldt to Joseph Albert Wright – Archival Traces
-Foni Le Brun-Ricalens, Leonardo López Luján, Claude Wey: Alexander von Humboldts „Aztekische Priesterin“ alias die Chalchiuhtlicue aus der Sammlung Guillermo Dupaix. Historiografischer Essay einer Translokation von Mexico-Stadt nach London
-Eberhard Knobloch: Leibniz und Alexander von Humboldt
-Irene Prüfer Leske: Wie stand es nun wirklich um Bonpland? Kritische Überlegungen zu Frank Holls Untersuchung zu Bonpland, seiner Beziehung zu Alexander von Humboldt und der Darstellung der letzten Tage von Bonpland durch Avé-Lallemant
-Leonhard Salzer, Anna Nöbauer: (Auf) Humboldts Spuren Eine bauforscherische Untersuchung der „Casa Humboldt“ am Antisana in Ecuador
-Renate Sternagel: Alexander von Humboldt, Therese von Bacheracht, und die „verhängnissvolle Prosa des Lebens“
-Ulrich Stottmeister: Der Mineraloge August Schmidt und die Entdeckung der Ural-Diamanten 1829 Teil I: Schmidts Weg in den Ural und die Diamanten-Vorhersage
-Kurt-R. Biermann (1919 – 2002) und Ingo Schwarz: Der polyglotte Alexander von Humboldt (mit einer Vorbemerkung von Jürgen Trabant)
-Tobias Kraft: Filología nómada. Repensar la obra de Alexander von Humboldt con la obra de Ottmar Ette (y viceversa
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