Entanglement genesis by ancilla-based parity measurement in 2D circuit QED

We present an indirect two-qubit parity meter in planar circuit quantum electrodynamics, realized by discrete interaction with an ancilla and a subsequent projective ancilla measurement with a dedicated, dispersively coupled resonator. Quantum process tomography and successful entanglement by measurement demonstrate that the meter is intrinsically quantum non-demolition. Separate interaction and measurement steps allow commencing subsequent data qubit operations in parallel with ancilla measurement, offering time savings over continuous schemes.Comment: 5 pages, 4 figures; supplemental material with 5 figure

Feature-based generation of pervasive systems architectures utilizing software product line concepts

As the need for pervasive systems tends to increase and to dominate the computing discipline, software engineering approaches must evolve at a similar pace to facilitate the construction of such systems in an efficient manner. In this thesis, we provide a vision of a framework that will help in the construction of software product lines for pervasive systems by devising an approach to automatically generate architectures for this domain. Using this framework, designers of pervasive systems will be able to select a set of desired system features, and the framework will automatically generate architectures that support the presence of these features. Our approach will not compromise the quality of the architecture especially as we have verified that by comparing the generated architectures to those manually designed by human architects. As an initial step, and in order to determine the most commonly required features that comprise the widely most known pervasive systems, we surveyed more than fifty existing architectures for pervasive systems in various domains. We captured the most essential features along with the commonalities and variabilities between them. The features were categorized according to the domain and the environment that they target. Those categories are: General pervasive systems, domain-specific, privacy, bridging, fault-tolerance and context-awareness. We coupled the identified features with well-designed components, and connected the components based on the initial features selected by a system designer to generate an architecture. We evaluated our generated architectures against architectures designed by human architects. When metrics such as coupling, cohesion, complexity, reusability, adaptability, modularity, modifiability, packing density, and average interaction density were used to test our framework, our generated architectures were found comparable, if not better than the human generated architectures

Neural Correlates of Spontaneous BOLD Fluctuations: A Simultaneous LFP-fMRI Investigation In The Non-human Primate

Resting-state functional magnetic resonance imaging (rs-fMRI) is widely used to explore functional connectivity (FC) between brain regions across neurological and psychiatric diseases. However, the neural basis of spontaneous low frequency blood-oxygen level dependent (BOLD) fluctuations is poorly understood. Here, we acquired rs-fMRI data in macaque monkeys together with simultaneous recordings of local field potentials (LFPs) in prefrontal cortex area 9/46d. We first evaluated the correlation between LFPs (1-100 Hz) and BOLD signals and found unique frequency power correlates of positive and negative FC. Anti-correlation of high and low power envelopes indicated that ongoing cross-frequency interactions are a neural correlate of FC. On the other hand, seed-based analysis of the BOLD signal from the vicinity of electrode revealed the same spatial topology when using the power envelopes of high frequency bands of LFPs in the regression analysis. Variations of the canonical hemodynamic response function (HRF) in distinct cortical areas were also investigated to find the optimal HRF that can best fit in model analysis and estimate the BOLD response. While we found the optimal HRF that yields the highest correlation, the HRF shape was consistent within subjects and between brain regions. Our results suggest that intrinsic connectivity networks may be specifically driven by unique LFP profiles and these profiles contribute differently to BOLD FC. This study provides insight into the neural correlates of spontaneous BOLD FC at rest

Designed extrudate for ceramic additive manufacturing

The objective of this thesis work was to design ceramic paste systems that assist in achieving a high theoretical density ( \u3e 95%) after deposition by a novel additive manufacturing process, i.e. Ceramic On-Demand Extrusion (CODE). The work is encompassed in five main sections: Sections 1 and 2 provide an introduction and literature review of relevant topics for the following sections of experimentation. Section 3 provides an analysis of a reaction chemistry to identify three discrete materials that could be combined via CODE and result in zirconium diboride (ZrB2) post-sintering. Section 4 describes the development of a high solids loading, aqueous yttria-stabilized zirconia paste. This material was identified as the next viable technical ceramic system after alumina for addition to the CODE portfolio. Section 5 details the use of sol-synthesized pre-mullite composite powder to densify stoichiometric mullite at modest temperatures. Section 6 provides a conclusion to the research results provided in the preceding three sections, as well as future work outlined in Section 7 --Abstract, page iii

Non-degenerate parametric amplifiers based on dispersion engineered Josephson junction arrays

Determining the state of a qubit on a timescale much shorter than its relaxation time is an essential requirement for quantum information processing. With the aid of a new type of non-degenerate parametric amplifier, we demonstrate the continuous detection of quantum jumps of a transmon qubit with 90% fidelity in state discrimination. Entirely fabricated with standard two-step optical lithography techniques, this type of parametric amplifier consists of a dispersion engineered Josephson junction (JJ) array. By using long arrays, containing $10^3$ JJs, we can obtain amplification at multiple eigenmodes with frequencies below $10~\mathrm{GHz}$, which is the typical range for qubit readout. Moreover, by introducing a moderate flux tunability of each mode, employing superconducting quantum interference device (SQUID) junctions, a single amplifier device could potentially cover the entire frequency band between 1 and $10~\mathrm{GHz}$.Comment: P.W. and I.T. contributed equally. 9 pages, 5 figures and appendice

High mobility in OFDM based wireless communication systems

Orthogonal Frequency Division Multiplexing (OFDM) has been adopted as the transmission scheme in most of the wireless systems we use on a daily basis. It brings with it several inherent advantages that make it an ideal waveform candidate in the physical layer. However, OFDM based wireless systems are severely affected in High Mobility scenarios. In this thesis, we investigate the effects of mobility on OFDM based wireless systems and develop novel techniques to estimate the channel and compensate its effects at the receiver. Compressed Sensing (CS) based channel estimation techniques like the Rake Matching Pursuit (RMP) and the Gradient Rake Matching Pursuit (GRMP) are developed to estimate the channel in a precise, robust and computationally efficient manner. In addition to this, a Cognitive Framework that can detect the mobility in the channel and configure an optimal estimation scheme is also developed and tested. The Cognitive Framework ensures a computationally optimal channel estimation scheme in all channel conditions. We also demonstrate that the proposed schemes can be adapted to other wireless standards easily. Accordingly, evaluation is done for three current broadcast, broadband and cellular standards. The results show the clear benefit of the proposed schemes in enabling high mobility in OFDM based wireless communication systems.Orthogonal Frequency Division Multiplexing (OFDM) wurde als Übertragungsschema in die meisten drahtlosen Systemen, die wir täglich verwenden, übernommen. Es bringt mehrere inhärente Vorteile mit sich, die es zu einem idealen Waveform-Kandidaten in der Bitübertragungsschicht (Physical Layer) machen. Allerdings sind OFDM-basierte drahtlose Systeme in Szenarien mit hoher Mobilität stark beeinträchtigt. In dieser Arbeit untersuchen wir die Auswirkungen der Mobilität auf OFDM-basierte drahtlose Systeme und entwickeln neuartige Techniken, um das Verhalten des Kanals abzuschätzen und seine Auswirkungen am Empfänger zu kompensieren. Auf Compressed Sensing (CS) basierende Kanalschätzverfahren wie das Rake Matching Pursuit (RMP) und das Gradient Rake Matching Pursuit (GRMP) werden entwickelt, um den Kanal präzise, robust und rechnerisch effizient abzuschätzen. Darüber hinaus wird ein Cognitive Framework entwickelt und getestet, das die Mobilität im Kanal erkennt und ein optimales Schätzungsschema konfiguriert. Das Cognitive Framework gewährleistet ein rechnerisch optimales Kanalschätzungsschema für alle möglichen Kanalbedingungen. Wir zeigen außerdem, dass die vorgeschlagenen Schemata auch leicht an andere Funkstandards angepasst werden können. Dementsprechend wird eine Evaluierung für drei aktuelle Rundfunk-, Breitband- und Mobilfunkstandards durchgeführt. Die Ergebnisse zeigen den klaren Vorteil der vorgeschlagenen Schemata bei der Ermöglichung hoher Mobilität in OFDM-basierten drahtlosen Kommunikationssystemen

On Transmission System Design for Wireless Broadcasting

This thesis considers aspects related to the design and standardisation of transmission systems for wireless broadcasting, comprising terrestrial and mobile reception. The purpose is to identify which factors influence the technical decisions and what issues could be better considered in the design process in order to assess different use cases, service scenarios and end-user quality. Further, the necessity of cross-layer optimisation for efficient data transmission is emphasised and means to take this into consideration are suggested. The work is mainly related terrestrial and mobile digital video broadcasting systems but many of the findings can be generalised also to other transmission systems and design processes. The work has led to three main conclusions. First, it is discovered that there are no sufficiently accurate error criteria for measuring the subjective perceived audiovisual quality that could be utilised in transmission system design. Means for designing new error criteria for mobile TV (television) services are suggested and similar work related to other services is recommended. Second, it is suggested that in addition to commercial requirements there should be technical requirements setting the frame work for the design process of a new transmission system. The technical requirements should include the assessed reception conditions, technical quality of service and service functionalities. Reception conditions comprise radio channel models, receiver types and antenna types. Technical quality of service consists of bandwidth, timeliness and reliability. Of these, the thesis focuses on radio channel models and errorcriteria (reliability) as two of the most important design challenges and provides means to optimise transmission parameters based on these. Third, the thesis argues that the most favourable development for wireless broadcasting would be a single system suitable for all scenarios of wireless broadcasting. It is claimed that there are no major technical obstacles to achieve this and that the recently published second generation digital terrestrial television broadcasting system provides a good basis. The challenges and opportunities of a universal wireless broadcasting system are discussed mainly from technical but briefly also from commercial and regulatory aspectSiirretty Doriast

Synthesis, structure and scalability of macroscopic carbon nanotube fibre

Carbon nanotube fibre is one of the most promising new materials due to the excellent combination of macroscopic properties (mechanical, electrical and thermal) and its particular hierarchical structure. Individual CNT is defined as a basic structural block, thus, CNT fibre combines the properties of a solid monolithic material but coexists with mesoporous structure, providing a high surface area (260m²/g). Kilometres of continuous macroscopic fibre of control number of layers are synthesised, tailored by the addition of sulphur as a catalyst promoter during chemical vapour deposition (CVD) in the direct spinning process. Further chirality distribution is obtained in SWCNT sample, showing the predominance of arm-chair and metallic behaviour. Distribution of chirality angles matches with the theoretical predictions for CNTs produced by a molten catalyst. Polymer fibre spinning principles are inspired the highly oriented CNT fibre by reducing the entanglements in gas phase through CNT dilution. Increasing the friction during its furnace extraction until ratios over 17 times, compare to the carrier gas. The resulting fibre obtains mechanical properties similar to commercial fibre as Kevlar. Specific strength and Young´s modulus are in overall 1.1 GPa and 60GPa, respectively, tuning the strain from 23% to 8% with toughness over 80J/g. Moreover, electrical conductivity reached until 3.5 x 10⁵ S/m. Internal porous structures and the building block interactions are analysed in detail by BET, BJH and XRD techniques, illustrating the links presented at different scales. Finally, it is studied whether different critical parameters of the synthesis are reproducible scaling-up the process, permitting the development of macroscopic devices for different applications.Debido a la combinación de propiedades macroscópicas (mecánicas, eléctricas y térmicas) y su estructura jerarquizada, la fibra de nanotubos de carbono es uno de los materiales más prometedores. Los nanotubos de carbono actúan como bloques básicos en la fibra, de este modo, la fibra puede combinar las propiedades de un sólido monolítico, junto con la de una estructura mesoporosa, alcanzando una elevada área superficial (260m²/g). Mediante el método de hilado directo es posible la producción de kilómetros de fibra macroscópica continua, controlando el número de capas añadiendo azufre, que actúa como promotor del catalizador en la reacción de deposición química en fase vapor (CVD). Se ha determinado también la distribución de quiralidades en fibra de CNTs de una sola capa, siendo arm-chair la predominante, proporcionando a la fibra de un comportamiento metálico. Esta distribución de quiralidades encaja con las predicciones teóricas para tubos sintetizados por un catalizador en estado fundido. Se ha utilizado el conocimiento ya existente de las fibras poliméricas para conseguir la síntesis de fibras orientadas, reduciendo el número de entrecruzamientos mediante la dilución de la muestra en el aerogel. En estas condiciones de reacción es posible extraer la fibra hasta 17 veces más rápido que la velocidad del gas en el interior del reactor, incrementando la fricción que permite la orientación. Las propiedades mecánicas obtenidas son similares a las de fibras comerciales como el Kevlar, obteniendo valores de fuerza específica y módulo de 1.1 GPa y 60 GPa, respectivamente, pudiendo modificar la elongación entre el 23% y el 8%, con tenacidades del orden de 80J/g. Además, se logró obtener una conductividad de 3.5 x 10⁵ S/m. A través de técnicas como el BET, BJH y XRD es posible conocer las conexiones que existen en el interior de la fibra a diferentes escalas. Finalmente, parámetros críticos de la reacción han sido escalados, facilitando su aplicación en la industria, permitiendo el desarrollo de dispositivos macroscópicos para diferentes aplicaciones.Programa Oficial de Doctorado en Ciencia e Ingeniería de MaterialesPresidente: María Eugenia Rabanal Jiménez.- Secretario: Álvaro Ridruejo Rodríguez.- Vocal: Fernando Fresno Garcí

Area-power-delay trade-off in logic synthesis

This thesis introduces new concepts to perform area-power-delay trade-offs in a logic synthesis system. To achieve this, a new delay model is presented, which gives accurate delay estimations for arbitrary sets of Boolean expressions. This allows use of this delay model already during the very first steps of logic synthesis. Furthermore, new algorithms are presented for a number of different optimization tasks within logic synthesis. There are new algorithms to create prime irredundant Boo lean expressions, to perform technology mapping for use with standard cell generators, and to perform gate sizing. To prove the validity of the presented ideas, benchmark results are given throughout the thesis