Observing different quantum trajectories in cavity QED

The experimental observation of quantum jumps is an example of single open quantum systems that, when monitored, evolve in terms of stochastic trajectories conditioned on measurements results. Here we present a proposal that allows the experimental observation of a much larger class of quantum trajectories in cavity QED systems. In particular, our scheme allows for the monitoring of engineered thermal baths that are crucial for recent proposals for probing entanglement decay and also for entanglement protection. The scheme relies on the interaction of a three-level atom and a cavity mode that interchangeably play the roles of system and probe. If the atom is detected the evolution of the cavity fields follows quantum trajectories and vice-versa.Comment: 5 pages, 2 figure

On curvature coupling and quintessence fine-tuning

We discuss the phenomenological model in which the potential energy of the quintessence field depends linearly on the energy density of the spatial curvature. We find that the pressure of the scalar field takes a different form when the potential of the scalar field also depends on the scale factor and the energy momentum tensor of the scalar field can be expressed as the form of a perfect fluid. A general coupling was proposed to explain the current accelerating expansion of the Universe and solve the fine-tuning problem.Comment: 5 pages, 1 figure, v2: correct the comment on astro-ph/0509177, v3: significant changes are made to better present the paper;v4: use epl style, add new contents, conclusion remains, accepted for publication by Europhys. Let

Subacute Hypophysitis with Panhypopituitarism as First Presentation of HIV and Syphilis Coinfection

Infection by Treponema pallidum still represents a clinical challenge due to its various forms of presentation. HIV coinfection added diversity and changed the natural history of syphilis as a systemic infection. We present a rare case of subacute hypophysitis and panhypopituitarism due to an early active neurosyphilis in a previously unknown HIV coinfected patient.info:eu-repo/semantics/publishedVersio

Distant entanglement protected through artificially increased local temperature

In composed quantum systems, the presence of local dissipative channels causes loss of coherence and entanglement at a rate that grows with the temperature of the reservoirs. However, here we show that if temperature is artificially added to the system, entanglement decay can be significantly slowed down or even suppressed conditioned on suitable local monitoring of the reservoirs. We propose a scheme to implement the joint reservoir monitoring applicable in different experimental setups like trapped ions, circuit and cavity QED or quantum dots coupled to nanowires and we analyze its general robustness against detection inefficiencies and non-zero temperature of the natural reservoir

Effect of spatial inhomogeneity on the mapping between strongly interacting fermions and weakly interacting spins

A combined analytical and numerical study is performed of the mapping between strongly interacting fermions and weakly interacting spins, in the framework of the Hubbard, t-J and Heisenberg models. While for spatially homogeneous models in the thermodynamic limit the mapping is thoroughly understood, we here focus on aspects that become relevant in spatially inhomogeneous situations, such as the effect of boundaries, impurities, superlattices and interfaces. We consider parameter regimes that are relevant for traditional applications of these models, such as electrons in cuprates and manganites, and for more recent applications to atoms in optical lattices. The rate of the mapping as a function of the interaction strength is determined from the Bethe-Ansatz for infinite systems and from numerical diagonalization for finite systems. We show analytically that if translational symmetry is broken through the presence of impurities, the mapping persists and is, in a certain sense, as local as possible, provided the spin-spin interaction between two sites of the Heisenberg model is calculated from the harmonic mean of the onsite Coulomb interaction on adjacent sites of the Hubbard model. Numerical calculations corroborate these findings also in interfaces and superlattices, where analytical calculations are more complicated.Comment: 7 pages, 6 figure

FLOW IN POROUS ELEMENTS: A THEORETICAL AND EXPERIMENTAL ANALYSIS OF THE EFFECTS OF THE CAPILLARY EFFORTS CAUSED BY WATER PERCOLATION IN MASONRY POROUS ELEMENTS

The identification of cracks in masonry bricks is quite common, not only after the edification but also during the process. Moistness absorbed by the elements of the wall (bricks and mortar) is one those factors. This moistness comes from the air, rain, soil absorption and even the excess of water in the laying mortar. In contact with the wall porous elements, the moistness will contribute to the capillary percolation, giving berth to considerable internal efforts which will induce the presence of cracks. This study leads to an analysis for the obtainment of fluid pressure and velocity medium values, measuring the deformation of the elements. The paper brings the equating to predict and estimate the velocities and efforts medium values in the ceramics elements. The flow in porous elements is studied and a proposal of modelingto estimate Velocities and Efforts values is presented

The development of intergroup bias in childhood: how social norms can shape children's racial behaviours

WOS:000261922300005 (Nº de Acesso Web of Science)The present research examined the developmental course of racial behaviours in childhood. It tested the hypothesis that White children's expressions of racial prejudice do not necessarily decline in middle childhood due to the development of particular cognitive skills but that instead, as argued by the socio-normative approach, children older than seven will go on expressing prejudiced attitudes under appropriate conditions. This would be explained by the presence of an anti-racism norm, along with the existence of values promoting equal rights, which impede blatant expressions of racism. In the first study 283 White children aged 6-7 and 9-10 years performed a task of resource allocation to White and Black target children in conditions of high (White interviewer was present) or low (White interviewer was absent) salience of the anti-racist norm. The 6- to 7-year-old children discriminated against the Black target in both conditions whereas older children discriminated against the Black child only when the anti-racist norm was not salient. In Study 2, 187 White children aged 6- 7 and 9-10 years performed the same resource allocation task in conditions of explicit activation of similarity vs dissimilarity or egalitarian vs merit-based norms regarding race relations. Supporting the hypothesis of the role of racist or anti-racist norms on the expression of intergroup discrimination, results have again shown that 6- to 7year-old children discriminated against the Black target in both conditions while older children presented significantly different prejudiced/nonprejudiced behaviours consistent with the activated norms. These results were discussed in terms of the need for a reanalysis of the assumptions and research results of the cognitive-developmental theory and of further developments in the socio-normative approach regarding the development of prejudice in childhood

EVALUATION OF MECHANICAL RESISTANCE BY THE FINITE ELEMENTS METHOD OF A MACHINING TOOL WITH INTERNAL COOLING CHANNELS

In this work, the strength of machining hardware for the modified turning process with internal channels that circulates water as a coolant through a closed system was studied. As output parameters, the mechanical strength at the cutting edge and in the grooves was studied. In addition, input parameters were considered different force and thermal flow conditions generated in the tool's cutting edge. All analyzes performed: Influence of temperature on tool stress, comparison of the maximum stresses in the tool channels with the cutting edge, and the influence of coolant stress in the internal channels were performed using the finite element method by the Ansys® Workbench software 19.2. The main conclusions were that the parameter that most influences the tension exerted on the tools is the force and that, according to the force exerted, the tool will not resist the tension efforts.