A tunable rf SQUID manipulated as flux and phase qubit

We report on two different manipulation procedures of a tunable rf SQUID. First, we operate this system as a flux qubit, where the coherent evolution between the two flux states is induced by a rapid change of the energy potential, turning it from a double well into a single well. The measured coherent Larmor-like oscillation of the retrapping probability in one of the wells has a frequency ranging from 6 to 20 GHz, with a theoretically expected upper limit of 40 GHz. Furthermore, here we also report a manipulation of the same device as a phase qubit. In the phase regime, the manipulation of the energy states is realized by applying a resonant microwave drive. In spite of the conceptual difference between these two manipulation procedures, the measured decay times of Larmor oscillation and microwave-driven Rabi oscillation are rather similar. Due to the higher frequency of the Larmor oscillations, the microwave-free qubit manipulation allows for much faster coherent operations.Comment: Proceedings of Nobel Symposium "Qubits for future quantum computers", Goeteborg, Sweden, May 25-28, 2009; to appear in Physica Script

Tunable Flux Qubit manipulated by fast pulses: operating requirements, dissipation and decoherence

A double SQUID manipulated by fast magnetic flux pulses can be used as a tunable flux qubit. In this paper we study the requirements for the qubit operation, and evaluate dissipation and decoherence due to the manipulation for a typical system. Furthermore, we discuss the possibility to use an integrated Rapid Single Flux Quantum logic for the qubit control.Comment: 6 pages, 4 figure

Paper Tiger or Game-Changer? Challenges of and Opportunities for EU Engagement with the Eurasian Economic Union. Bruges Regional Integration & Global Governance Papers (BRIGG) 1/2015.

The Eurasian Economic Union (EEU) started work on 1 January 2015. Considered as Russia’s response to the EU’s Eastern Partnership (EaP), it has been almost ignored in Brussels. However, with the Ukraine crisis and the deteriorating relations with Moscow, some European leaders have begun to reconsider Putin’s proposal for a region-to-region engagement. This paper tries to analyse under which conditions this could represent a long-term solution for a new European order. First, it is argued that the EEU is still far from being a credible international interlocutor. Second, Russia’s commitment to international trade rules and liberalization is questioned, whereas its geopolitical objectives seem predominant. EU engagement with the EEU in Ukraine would mean, in the short term, legitimizing Russia’s vision of a ‘bipolar Europe’ divided in spheres of influence. In the long run, prospects for inter-regional cooperation remain open, but the way to go is long and full of obstacles

Paper tiger or game-changer? Challenges of and opportunities for EU engagement with the Eurasian Economic Union. Bruges Regional Integration & Global Governance Papers 1/2015

The Eurasian Economic Union (EEU) started work on 1 January 2015. Considered as Russia’s response to the EU’s Eastern Partnership (EaP), it has been almost ignored in Brussels. However, with the Ukraine crisis and the deteriorating relations with Moscow, some European leaders have begun to reconsider Putin’s proposal for a region-to-region engagement. This paper tries to analyse under which conditions this could represent a long-term solution for a new European order. First, it is argued that the EEU is still far from being a credible international interlocutor. Second, Russia’s commitment to international trade rules and liberalization is questioned, whereas its geopolitical objectives seem predominant. EU engagement with the EEU in Ukraine would mean, in the short term, legitimizing Russia’s vision of a ‘bipolar Europe’ divided in spheres of influence. In the long run, prospects for inter-regional cooperation remain open, but the way to go is long and full of obstacles

El tipo chalet californiano en la arquitectura doméstica del noroeste argentino : Tucumán y Salta, 1930- 1950

Este trabajo tiene como objeto de estudio a las viviendas que se realizaron en Tucumán y Salta en el período 1930-1955 siguiendo al tipo chalet californiano. Este tipo constituye uno de los modelos habitacionales que más aceptación ha tenido en el país, pudiendo ser considerado un tipo emblemático de la cultura arquitectónica de la primera mitad del siglo XX. Este trabajo pretende comprender los mecanismos de introducción del tipo en la región, a la vez que analizar cómo se realizaron las apropiaciones locales a este modelo foráneo: ¿Cómo el modelo, originalmente rural o suburbano, se adaptó a un medio urbano? ¿Cuáles fueron las interpretaciones formales y simbólicas que los diferentes actores realizaron? Para ello se analizaron cualitativamente ejemplos claves y se cotejaron con los principales rasgos del tipo original. Finalmente el trabajo reflexiona sobre la impronta de este tipo en el patrimonio doméstico de Tucumán y Salta hoy.This work has as object of study to dwellings that were made in Tucumán and Salta in the period 1930-1955 following the "Mission Style chalet" type. This type is one of the housing models that more acceptance has had on the country, and can be considered a symbolic type of architectural culture of the first half of the 20th century. This work seeks to understand the mechanisms of introduction of the kind in the region, and to analyze how local appropriations were made to this foreign model: how the model, originally rural or suburban, adapted to an urban environment?. What were formal and symbolic interpretations which were carried out by different actors? This key examples were qualitatively analyzed and compared with the main features of the original type. Finally the work reflects on the imprint of this type in the domestic heritage of Tucumán and Salta today.Fil: Chiarello, Ana Lía. Universidad Nacional de Tucumá

Amplitude-Multiplexed readout of single photon detectors based on superconducting nanowires

The realization of large-scale photonic circuit for quantum optics experiments at telecom wavelengths requires an increasing number of integrated detectors. Superconductive nanowire single photon detectors (SNSPDs) can be easily integrated on chip and they can efficiently detect the light propagating inside waveguides. The thermal budget of cryostats poses a limit on the maximum number of elements that can be integrated on the same chip due to the thermal impact of the readout electronics. In this paper, we propose and implement a novel scheme able for an efficient reading of several SNSPDs with only one readout port, enabling the realization of photonic circuits with a large number of modes

Droplet breakup driven by shear thinning solutions in a microfluidic T-Junction

Droplet-based microfluidics turned out to be an efficient and adjustable platform for digital analysis, encapsulation of cells, drug formulation, and polymerase chain reaction. Typically, for most biomedical applications, the handling of complex, non-Newtonian fluids is involved, e.g. synovial and salivary fluids, collagen, and gel scaffolds. In this study we investigate the problem of droplet formation occurring in a microfluidic T-shaped junction, when the continuous phase is made of shear thinning liquids. At first, we review in detail the breakup process providing extensive, side-by-side comparisons between Newtonian and non-Newtonian liquids over unexplored ranges of flow conditions and viscous responses. The non-Newtonian liquid carrying the droplets is made of Xanthan solutions, a stiff rod-like polysaccharide displaying a marked shear thinning rheology. By defining an effective Capillary number, a simple yet effective methodology is used to account for the shear-dependent viscous response occurring at the breakup. The droplet size can be predicted over a wide range of flow conditions simply by knowing the rheology of the bulk continuous phase. Experimental results are complemented with numerical simulations of purely shear thinning fluids using Lattice Boltzmann models. The good agreement between the experimental and numerical data confirm the validity of the proposed rescaling with the effective Capillary number.Comment: Manuscript: 11 pages 5 figures, 65 References. Textual Supplemental Material: 6 pages 3 figure. Video Supplemental Materials: 2 movie