3,407 research outputs found
The origin of non-classical effects in a one-dimensional superposition of coherent states
We investigate the nature of the quantum fluctuations in a light field created by the superposition of coherent fields. We give a physical explanation (in terms of Wigner functions and phase-space interference) why the 1-D superposition of coherent states in the direction of the x-quadrature leads to the squeezing of fluctuations in the y-direction, and show that such a superposition can generate the squeezed vacuum and squeezed coherent states
Quantum calculation of vortices in the inner crust of neutron stars
We study, within a quantum mechanical framework based on self-consistent mean
field theory, the interaction between a vortex and a nucleus immersed in a sea
of free neutrons, a scenario representative of the inner crust of neutron
stars. Quantal finite size effects force the vortex core outside the nucleus,
influencing vortex pinning in an important way
Coherent states superpositions in cavity quantum electrodynamics with trapped ions
We investigate how superpositions of motional coherent states naturally arise
in the dynamics of a two-level trapped ion coupled to the quantized field
inside a cavity. We extend our considerations including a more realistic set up
where the cavity is not ideal and photons may leak through its mirrors. We
found that a detection of a photon outside the cavity would leave the ion in a
pure state. The statistics of the ionic state still keeps some interference
effects that might be observed in the weak coupling regime.Comment: Figure and typos correcte
Live Demonstration: Retinal ganglion cell software and FPGA implementation for object detection and tracking
This demonstration shows how object detection and
tracking are possible thanks to a new implementation which
takes inspiration from the visual processing of a particular type
of ganglion cell in the retina
Retinal ganglion cell software and FPGA model implementation for object detection and tracking
This paper describes the software and FPGA
implementation of a Retinal Ganglion Cell model which detects
moving objects. It is shown how this processing, in conjunction
with a Dynamic Vision Sensor as its input, can be used to
extrapolate information about object position. Software-wise, a
system based on an array of these of RGCs has been developed in
order to obtain up to two trackers. These can track objects in a
scene, from a still observer, and get inhibited when saccadic
camera motion happens. The entire processing takes on average
1000 ns/event. A simplified version of this mechanism, with a mean
latency of 330 ns/event, at 50 MHz, has also been implemented in
a Spartan6 FPGA.European Commission FP7-ICT-600954Ministerio de Economía y Competitividad TEC2012-37868-C04-02Junta de Andalucía P12-TIC-130
Descripción de tres nuevas especies de tetigónidos de Costa Rica (Orthoptera, Tettigoniidae)
Se describen tres nuevas especies de tetigónidos procedentes de la Reserva Biológica Alberto Manuel Brenes (Alajuela) en Costa Rica (Centroamérica). El material se recolectó en virtud del proyecto INVARTRAB desarrollado conjuntamente entre la Universidad Central de Costa Rica y el INIA de Madrid (España). Los ejemplares fueron capturados mediante muestreo directo sobre la vegetación y mediante trampas de luz. Las nuevas especies pertenecen a los géneros Phlugis, Scopiorinus y Viadana respectivamente. Phlugis ramirezi sp. n. se caracteriza por presentar tegminas y alas poco desarrolladas, décimo terguito abdominal del macho acabado en dos procesos espiniformes, y el cerco curvado con un espolón basal y el ápice dilatado con cuatro dientes. Scopiorinus estebani sp. n. presenta el décimo terguito abdominal del macho expandido en un proceso más largo que ancho y la placa subgenital escotada en el centro y con dos procesos espiniformes laterales en el ápice. Viadana rowelli sp. n. presenta tegminas romboidales y el cerco del macho con una ramificación con el ápice aserrado insertada en el último tercio. Se ilustran las estructuras que las caracterizan y se comparan con las especies afines dentro de cada género.Description of three new species of katydids from Costa Rica (Orthoptera, Tettigoniidae)
Three new species of katydids from the Reserva Biológica Alberto Manuel Brenes (Alajuela) in Costa Rica (Central America) are described. The specimens were collected in the course of the Project INVARTRAB developed by the Central University of Costa Rica and the INIA de Madrid (España). The specimens were sampled by direct prospection on plants and light traps. The new species belong to the genera Phlugis, Scopiorinus and Viadana, respectively. Phlugis ramirezi n. sp. has little developed tegmens and wings, male tenth abdominal tergite ending in two spiniform processes, cerci curved with a basal spur, and four teeth in the apex. Scopiorinus estebani n. sp. shows male tenth abdominal tergite with a longer than broad expansion, subgenital plate depressed in the middle, and lateral spiniform processes at the end. Viadana rowelli n. sp. has rhomboidal tegmens and male cerci with an internal branch with serrulated apex inserted in the last third. Main characters are illustrated and compared in related species in each genus.Se describen tres nuevas especies de tetigónidos procedentes de la Reserva Biológica Alberto Manuel Brenes (Alajuela) en Costa Rica (Centroamérica). El material se recolectó en virtud del proyecto INVARTRAB desarrollado conjuntamente entre la Universidad Central de Costa Rica y el INIA de Madrid (España). Los ejemplares fueron capturados mediante muestreo directo sobre la vegetación y mediante trampas de luz. Las nuevas especies pertenecen a los géneros Phlugis, Scopiorinus y Viadana respectivamente. Phlugis ramirezi sp. n. se caracteriza por presentar tegminas y alas poco desarrolladas, décimo terguito abdominal del macho acabado en dos procesos espiniformes, y el cerco curvado con un espolón basal y el ápice dilatado con cuatro dientes. Scopiorinus estebani sp. n. presenta el décimo terguito abdominal del macho expandido en un proceso más largo que ancho y la placa subgenital escotada en el centro y con dos procesos espiniformes laterales en el ápice. Viadana rowelli sp. n. presenta tegminas romboidales y el cerco del macho con una ramificación con el ápice aserrado insertada en el último tercio. Se ilustran las estructuras que las caracterizan y se comparan con las especies afines dentro de cada género
Surface properties of nuclear pairing with the Gogny force in a simplified model
Surface properties of neutron-neutron (T=1) pairing in semi-infinite nuclear
matter in a hard wall potential are investigated in BCS approximation using the
Gogny force. Surface enhancement of the gap function, pairing tensor and
correlation energy density is put into evidence.Comment: 16 pages; 4 figures ; submitted to Phys. Lett.
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