Sagnac rotational phase shifts in a mesoscopic electron interferometer with spin-orbit interactions

The Sagnac effect is an important phase coherent effect in optical and atom interferometers where rotations of the interferometer with respect to an inertial reference frame result in a shift in the interference pattern proportional to the rotation rate. Here, we analyze the Sagnac effect in a mesoscopic semiconductor electron interferometer. We include in our analysis the Rashba spin-orbit interactions in the ring. Our results indicate that spin-orbit interactions increase the rotation-induced phase shift. We discuss the potential experimental observability of the Sagnac phase shift in such mesoscopic systems.

Quantum control of electromagnetically induced transparency dispersion via atomic tunneling in a double-well Bose-Einstein condensate

Electromagnetically induced transparency (EIT) is an important tool for controlling light propagation and nonlinear wave mixing in atomic gases with potential applications ranging from quantum computing to table top tests of general relativity. Here we consider EIT in an atomic Bose-Einstein condensate (BEC) trapped in a double-well potential. A weak probe laser propagates through one of the wells and interacts with atoms in a three-level Lambda configuration. The well through which the probe propagates is dressed by a strong control laser with Rabi frequency Omega(mu), as in standard EIT systems. Tunneling between the wells at the frequency g provides a coherent coupling between identical electronic states in the two wells, which leads to the formation of interwell dressed states. The macroscopic interwell coherence of the BEC wave function results in the formation of two ultranarrow absorption resonances for the probe field that are inside of the ordinary EIT transparency window. We show that these new resonances can be interpreted in terms of the interwell dressed states and the formation of a type of dark state involving the control laser and the interwell tunneling. To either side of these ultranarrow resonances there is normal dispersion with very large slope controlled by g. We discuss prospects for observing these ultranarrow resonances and the corresponding regions of high dispersion experimentally.

Effects of a quantum measurement on the electric conductivity : Application to graphene

We generalize the standard linear-response (Kubo) theory to obtain the conductivity of a system that is subject to a quantum measurement of the current. Our approach can be used to specifically elucidate how back-action inherent to quantum measurements affects electronic transport. To illustrate the utility of our general formalism, we calculate the frequency-dependent conductivity of graphene and discuss the effect of measurement-induced decoherence on its value in the dc limit. We are able to resolve an ambiguity related to the parametric dependence of the minimal conductivity.

Refraction in spacetime

Refraction, interference, and diffraction are distinguishing features of wavelike phenomena. Although they are usually associated only with a purely spatial wave-propagation pattern, analogs to interference and diffraction involving the spatio-temporal dynamics of waves in one dimension have been discussed. We complete the triplet of analogies by discussing how spatio-temporal analogs to refraction are exhibited by a quantum particle in one dimension that is scattering off a step barrier. Similarly, birefringence in spacetime occurs for a spin-1/2 particle in a magnetic field.

Gravitational self-localization for spherical masses

In this work, I consider the center-of-mass wave function for a homogenous sphere under the influence of the self-interaction due to Newtonian gravity. I solve for the ground state numerically and calculate the average radius as a measure of its size. For small masses, M≲10−17 kg, the radial size is independent of density, and the ground state extends beyond the extent of the sphere. For masses larger than this, the ground state is contained within the sphere and to a good approximation given by the solution for an effective radial harmonic-oscillator potential. This work thus determines the limits of applicability of the point-mass Newton Schrödinger equations for spherical masses. In addition, I calculate the fringe visibility for matter-wave interferometry and find that in the low-mass case, interferometry can in principle be performed, whereas for the latter case, it becomes impossible. Based on this, I discuss this transition as a possible boundary for the quantum-classical crossover, independent of the usually evoked environmental decoherence. The two regimes meet at sphere sizes R≈10−7 m, and the density of the material causes only minor variations in this value.

Setor informal da economia e a dinâmica dos territórios nas praias da cidade do Natal/RN

La recherche sur secteur non-formel de l économie et la dynamique des territoires dans les plages de la ville de Natal/RN, a le but de la compréhension des espaces de ces territoires ainsi que leurs caractéristiques; le rapport des acteurs sociaux et l existence de politiques dirigées direct ou indirectement vers ce secteur de l économie et ses territoires. Pour celà, on donne emphase au scénario économique moulé par le système de production et reproduction dans la mondialisation, ce qui, parmis d autres actions aq l inetrférence sur le marché du travail, lequel subit constamment des transformations importantes cherchant à suivre les changements en niveau global, en devenant, pour ainsi dire, un marché chaque fois plus exigeant et, conséquemment, sélectif. Moyennant la réalité économique et politique vécue, il augmente le nombre de chômeurs dans le pays suscitant, à tort et à travers, la croissance du secteur non-formel de l économie avec ses inombrables travailleurs qui occupent les plus différents segments parmi lesquels les travaux autonomes, ici représentés par les camelots, les propriétaires de baraques, les propriétaires de kiosques ; etc. Pour atteindre ce but, on a cherché les reférenciels théorico-scientifiques ayant pour base la connaissance empirique à travers les inombrables cas d études matérialisés au moyen de donnés primaires et sécondaires. Finalement, on est sûr de ce que les travailleurs du secteur non-formel complèmentent la chaîne repoductive, ils créent et recréent des territoires avec des contenus variés qui sont indispensables pour la croissance et le développement social

Os sentidos da liberdade... A gíria prisional como resultado de uma produção léxica criativa e significativa

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Arquitectura de la vivienda social en centros históricos. dialogos entre el tiempo del diseño y el tiempo del uso social. edificio Riachuelo, San Pablo, Brasil

El Ayuntamiento de San Pablo, en la gestión de 2001 a 2004, pretendió atender a la demanda de habitación social implementando el Programa Social: “Vivir en el Centro” a través de los proyectos: “Perímetros de Rehabilitación Integrada del Habitat” (PRIH), “Alquiler Social”, “Programa de Arrendamiento Residencial” (PAR), “Bolsa Alquiler”, “Vivienda Transitoria” y “Programa de Intervención en Viviendas Hacinadas”. A través del “Programa de Arrendamiento Residencial” fueron implementados los siguientes edificios: Hotel San Pablo, Riskallah Jorge, Brigadeiro Tobias, Riachuelo, entre otros. En este contexto, el objetivo de la presente investigación es analizar el diálogo existente entre el tiempo del diseño y el tiempo del uso social de la vivienda social del edificio Riachuelo. Métodos: los diálogos entre el tiempo del diseño y el tiempo del uso social de la vivienda fueron realizados a partir de las entrevistas con los autores del proyecto de arquitectura y los residentes del edificio. Para conocer la obra construida fueron consultados los proyectos de arquitectura y se realizaron visitas técnicas al edificio. La investigación contribuye con: i) los estudios de la vivienda social de los programas públicos en centros históricos, ii) la reutilización de edificios y iii) la calidad de los diseños o proyectos de arquitectura.

Ambientes de confluência no contexto da rede de drenagem: exemplo da bacia hidrográfica do rio Ivaí - estado do Paraná

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ambientes de confluência no contexto da rede de drenagem: exemplo da bacia hidrográfica do rio Ivaí - estado do Paraná

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of valsartan on the incidence of diabetes and cardiovascular events

It is not known whether drugs that block the renin-angiotensin system reduce the risk of diabetes and cardiovascular events in patients with impaired glucose tolerance.

Effect of nateglinide on the incidence of diabetes and cardiovascular events

The ability of short-acting insulin secretagogues to reduce the risk of diabetes or cardiovascular events in people with impaired glucose tolerance is unknown.

Identifying specific interpretations and use of safety behaviours in people with distressing visual hallucinations: an exploratory study

Visual hallucinations (VH) are a common experience and can be distressing and disabling, particularly for people suffering from psychotic illness. However, not everyone with visual hallucinations reports the experience to be distressing. Models of VH propose that appraisals of VH as a threat to wellbeing and the use of safety seeking behaviours help maintain the distress.