1,791 research outputs found
Propuesta de arquitectura para un software educativo en el dominio de la enseñanza de la física que concilie el modelo del negocio con las mejores prácticas de las ciencias de la computación
Muchos son los trabajos que proponen directrices para la utilización del software como recurso en el ámbito de la enseñanza de la física. Sin embargo, se mantiene como un tema no resuelto lo relativo a los aspectos tecnológicos y pedagógicos que deben ser contemplados en su diseño y evaluación. Lo anterior implica la consideración de las características del negocio educativo y la identificación de los requerimientos propios de la Enseñanza de la Física; además de la aplicación de principios inherentes a la Ingeniería del Software. La metodología de diseño arquitectónico que se propone comienza con el análisis detallado de requerimientos y el modelado del negocio educativo y se centra en la generación de una arquitectura base, cuya estructura es condicionada por requisitos de calidad, aplicada a un caso de estudio en el dominio de la Enseñanza de la Física
Experimental evidence for the breakdown of a Hartree-Fock approach in a weakly interacting Bose gas
We study the formation of a quasi-condensate in a nearly one dimensional,
weakly interacting trapped atomic Bose gas. We show that a Hartree Fock
(mean-field) approach fails to explain the presence of the quasi-condensate in
the center of the cloud: the quasi-condensate appears through an
interaction-driven cross-over and not a saturation of the excited states.
Numerical calculations based on Bogoliubov theory give an estimate of the
cross-over density in agreement with experimental results.Comment: submitted to Phys. Rev. Letter
Multi-mode storage and retrieval of microwave fields in a spin ensemble
A quantum memory at microwave frequencies, able to store the state of
multiple superconducting qubits for long times, is a key element for quantum
information processing. Electronic and nuclear spins are natural candidates for
the storage medium as their coherence time can be well above one second.
Benefiting from these long coherence times requires to apply the refocusing
techniques used in magnetic resonance, a major challenge in the context of
hybrid quantum circuits. Here we report the first implementation of such a
scheme, using ensembles of nitrogen-vacancy (NV) centres in diamond coupled to
a superconducting resonator, in a setup compatible with superconducting qubit
technology. We implement the active reset of the NV spins into their ground
state by optical pumping and their refocusing by Hahn echo sequences. This
enables the storage of multiple microwave pulses at the picoWatt level and
their retrieval after up to s, a three orders of magnitude improvement
compared to previous experiments.Comment: 8 pages, 5 figures + Supplementary information (text and 6 figures
Rapport fait au nom de la commission de l'agriculture sur la proposition de resolution de MM. Bourges et Esteve (doc. 134, 1964-1965) tendant a inviter la Communaute economique europeenne a deposer un projet de reglement communitaire pour l'organisation du marche de la pomme de terre-primeur avec aide et soutien du F.E.O.G.A. Documents de seance 1965-1966, Document 25, 4 Mai 1965. = "Report on behalf of the Committee on Agriculture on the proposal of resolution from Misters Bourges and Esteve (Doc. 134, 1964-1965) tending to invite the European Economic Community to a project, Community regulations for organizing the walk-premier potatoes with help and support from the EAGGF. EP Working Documents 1965-1966, Document 25, 4 May 1965"
Revisión sistemática del trilobite oryctocefálido Protoryctocephalus arcticus Geyer & Peel, 2011 del Cámbrico inferior (Piso 4) de Balang, China meridional
The oryctocephalid trilobites from the traditional ‘lower-middle Cambrian’ represent key tools for international correlation. The trilobite zones in South China around the Cambrian Series 2-Miaolingian are made using oryctocephalids. One of the trilobite zones suggested is based on Protoryctocephalus arcticus. Protoryctocephalus from the Balang area in South China was described as Protoryctocephalus wuxunensis, also from the Cambrian Series 2 of South China. However, Protoryctocephalus from Balang shows different morphological features such as different glabellar shape, presence of a transglabellar S1 and more segments in the trunk. These features match with Protoryctocephalus arcticus from the Cambrian Series 2 of Greenland.Los trilobites oryctocefálidos del tránsito ‘Cámbrico inferior-medio’ representan herramientas clave para la correlación internacional. Las zonas de trilobites en China meridional a través del tránsito Serie cámbrica 2-Miaolingiense se basan en este grupo fósil. La base de una de estas zonas de trilobites se sitúa con la aparición de Protoryctocephalus arcticus. El género Protoryctocephalus, procedente del área de Balang en China meridional, fue descrito originalmente como Protoryctocephalus wuxunensis, también de la serie cámbrica 2 de China meridional. Sin embargo, en Balang Protoryctocephalus muestra diferentes caracteres morfológicos, tales como la forma glabelar, la presencia de un surco transglabelar S1 y más segmentos en el tronco (tórax + pigidio). Estos caracteres cuadran mejor con Protoryctocephalus arcticus de la Serie cámbrica 2 of Groenlandia
Storage and Retrieval of a Microwave Field in a Spin Ensemble
We report the storage and retrieval of a small microwave field from a
superconducting resonator into collective excitations of a spin ensemble. The
spins are nitrogen-vacancy centers in a diamond crystal. The storage time of
the order of 30 ns is limited by inhomogeneous broadening of the spin ensemble.Comment: 4 pages + supplementary material. Submitted to PR
Strong Coupling of a Spin Ensemble to a Superconducting Resonator
We report the realization of a quantum circuit in which an ensemble of
electronic spins is coupled to a frequency tunable superconducting resonator.
The spins are Nitrogen-Vacancy centers in a diamond crystal. The achievement of
strong coupling is manifested by the appearance of a vacuum Rabi splitting in
the transmission spectrum of the resonator when its frequency is tuned through
the NV center electron spin resonance.Comment: 4 pages, 3 figure
- …