12,011 research outputs found
Non-reciprocal few-photon devices based on chiral waveguide-emitter couplings
We demonstrate the possibility of designing efficient, non reciprocal
few-photon devices by exploiting the chiral coupling between two waveguide
modes and a single quantum emitter. We show how this system can induce
non-reciprocal photon transport at the single-photon level and act as an
optical diode. Afterwards, we also show how the same system shows a
transistor-like behaviour for a two-photon input. The efficiency in both cases
is shown to be large for feasible experimental implementations. Our results
illustrate the potential of chiral waveguide-emitter couplings for applications
in quantum circuitry.Comment: Mathematica notebook attached for calculation of detection
probabilitie
Elysia timida (Risso, 1818) three decades of research
Elysia timida (Risso, 1818) three decades of research.— During the last 30 years, studies on Elysia timida (Risso,
1818) have addressed various aspects related to food sources, photosynthetic efficiency of kleptoplasts, population
genetics, chemical ecology and reproductive biology, both in the Mediterranean Sea and in the Mar Menor
coastal lagoon. E. timida shows a strong specific interaction with Acetabularia acetabulum, retaining functional
chloroplasts for at least 45 days and obtaining extra energy in periods when food resources are scarce. It shows
control of parapodia, avoiding pigment photodestruction under oversaturated light conditions. The chemical ecological
relationships established between E. timida and its potential predator fish, Thalassoma pavo, have also
been evaluated, and it has been found that that the extracts of the mollusc contain repellent and unpalatable
polypropionate compounds. Population genetics has demonstrated the genetic divergence between populations
showing high and significant values of FST and genetic distances, and at least six privative alleles that are not
shared with Mediterranean populations have been detected in lagoon populations. This sacoglossan is a poecilogonic
species, and its lagoon populations show a greater reproductive output than Mediterranean populations; they
produce a greater number of egg masses and embyros per individual, and the capsules have a wider diameter
Didactic strategies for comprehension and learning of structural concepts
p. 926-937In previous papers we have established the convenience of formulating educational
strategies at the university level for both disciplines: Civil Engineering and Architecture,
which involves academic topics of mutual interest by means of shared practices. As a
particular matter of this approach, the application of physical experimental models is
considered of special usefulness, in order to understand in better ways the performance of materials and structural systems.
Several strategies of selection and development of such physical models will be discussed in this work, considering as a first step, the establishment of its correspondence with the different levels of structural complexity studied in curriculum plan: statics, strength of materials and structural design, among others.
This task constitutes a part of the work program of the Laboratory of Structural Models,
which is an academic project that develops and applies different didactic prototypes to
structure courses in the Universidad Autónoma Metropolitana, campus Azcapotzalco, in
Mexico City, project we have already presented in recent forums.
Two different modes of application are implemented in classroom sessions and in
structures workshop: the devices for functional demonstration of typical cases of structural work as well as the experimentation with student's own designs of destructible models where certain typologies are tested up to its failure limit.
The first one allows teachers to explain adequately the theoretical principles and formulas
(that usually are expressed on the blackboard) by means of didactic models identified in
accordance to specific cases of the curriculum on variable level of complexity. This kind of practice allows the students of architecture and civil engineering to realize in better ways the possibilities of use and application of the different structural typologies. Such
experimental models are part of more than fifty devices of the Laboratory's catalog.
In the same sense, the possibility of observation of structural work of their own
architectural designs, allows future professionals to achieve a better conception of the
structural solutions that affect positively their designs. Based on specific predefined guides, the students develop their own architectural-structural projects and subject them to diverse loads, observing their behavior under the influence of variable stresses leading up the experiment to its last resistance.
From both experiences a significant learning is obtained for the student's formation and
training, who will be capable in his future professional work to use better tools of
comprehension of the structural concepts applied to architecture as well as of increasing his conscience of the benefits and convenience of multidisciplinary work.Moreno, C.; Abad, A.; Gerdingh, JG.; Garcia M., C.; Gonzalez C., O. (2010). Didactic strategies for comprehension and learning of structural concepts. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/695
Entanglement of two qubits mediated by one-dimensional plasmonic waveguides
We investigate qubit-qubit entanglement mediated by plasmons supported by
one-dimensional waveguides. We explore both the situation of spontaneous
formation of entanglement from an unentangled state and the emergence of driven
steady-state entanglement under continuous pumping. In both cases, we show that
large values for the concurrence are attainable for qubit-qubit distances
larger than the operating wavelength by using plasmonic waveguides that are
currently available.Comment: 4 pages, 4 figures. Minor Changes. Journal Reference added.
Highlighted in Physic
Non-Markovian effects in waveguide-mediated entanglement
We study the generation and evolution of entanglement between two qubits
coupled through one-dimensional waveguide modes. By using a complete quantum
electrodynamical formalism we go beyond the Markovian approximation. The
diagonalization of the hamiltonian is carried out, and a set of quasi-localized
eigenstates is found. We show that when the qubit-waveguide coupling is
increased, the Markov approximation is not anymore valid, and the generation of
entanglement is worsened.Comment: 13 pages, 7 figure
Effects of the inclusion of oat hulls or sugar beet pulp in the diet on gizzard characteristics, apparent ileal digestibility of nutrients, and microbial count in the ceca in 36 day old broilers reared on floor
The effects of the inclusion of oat hulls (OH) and sugar beet pulp (SBP) in the diet on gizzard characteristics, apparent ileal nutrient digestibility (AID), and Clostridium perfringens, Enterobacteriaceae, and Lactobacillus proliferation in the ceca were studied in 36 d?old broilers. There were a control diet with a low CF content (1.61%) and 2 additional diets that resulted from the dilution of this feed with 5% of either OH or SBP
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