Adiabatic Charge Pumping through Quantum Dots in the Coulomb Blockade Regime

We investigate the influence of the Coulomb interaction on the adiabatic pumping current through quantum dots. Using nonequilibrium Green's functions techniques, we derive a general expression for the current based on the instantaneous Green's function of the dot. We apply this formula to study the dependence of the charge pumped per cycle on the time-dependent pumping potentials. The possibility of charge quantization in the presence of a finite Coulomb repulsion energy is investigated in the light of recent experiments.Comment: 11 pages, 10 figure

Spin-orbit mode transfer via a classical analog of quantum teleportation

We translate the quantum teleportation protocol into a sequence of coherent operations involving three degrees of freedom of a classical laser beam. The protocol, which we demonstrate experimentally, transfers the polarisation state of the input beam to the transverse mode of the output beam. The role of quantum entanglement is played by a non-separable mode describing the path and transverse degrees of freedom. Our protocol illustrates the possibility of new optical applications based on this intriguing classical analogue of quantum entanglement.Comment: 5 pages, 7 figure

Suppression of Anderson localization of light and Brewster anomalies in disordered superlattices containing a dispersive metamaterial

Light propagation through 1D disordered structures composed of alternating layers, with random thicknesses, of air and a dispersive metamaterial is theoretically investigated. Both normal and oblique incidences are considered. By means of numerical simulations and an analytical theory, we have established that Anderson localization of light may be suppressed: (i) in the long wavelength limit, for a finite angle of incidence which depends on the parameters of the dispersive metamaterial; (ii) for isolated frequencies and for specific angles of incidence, corresponding to Brewster anomalies in both positive- and negative-refraction regimes of the dispersive metamaterial. These results suggest that Anderson localization of light could be explored to control and tune light propagation in disordered metamaterials.Comment: 4 two-column pages, 3 figure

Fungal Meningitis in an Immunocompetent Patient

Cryptococcal meningitis is a rare entity among immunocompetent hosts but, when it occurs, it is associated with significant morbidity and mortality. Clinical presen- tation as well as the course of the disease is usually subtle and indolent with headache and altered mental status. The authors present the case of a 59-year-old man, who sought medical help with a 2-week history of headaches accompanied by nausea and visual and hearing disturbances. On admission the patient was afebrile, presented visual and hearing deficits and had a normal magnetic resonance image of the brain. A lumbar puncture was performed and microscopic examination of the cerebrospinal fluid revealed yeasts that were identified as Cryptococcus spp. and later, by means of molecular biology techniques, as Cryptococcus neoformans, var. grubii. The patient was treated with liposomal amphotericin B plus fluconazole for 28 weeks. At follow-up after 1 year the patient was asymptomatic and received fluconazole 400 mg/day as prophylactic therapy. The outcome of Cryptococcus infections in immunocompetent hosts is reported to be poor as a result of a delayed diagnosis and suboptimal initial antifungal therapy. The influence of the normal immune response is unclear

Geometry of static perfect fluid space-time

In this article, we investigate the geometry of static perfect fluid space-time on compact manifolds with boundary. We use the generalized Reilly's formula to establish a geometric inequality for a static perfect fluid space-time involving the area of the boundary and its volume. Moreover, we obtain new boundary estimates for static perfect fluid space-time. One of the boundary estimates is obtained in terms of the Brown-York mass and another one related to the first eigenvalue of the Jacobi operator. In addition, we provide a new (simply connected) counterexample to the Cosmic no-hair conjecture for arbitrary dimension $n\geq 4.$Comment: 21 page

A escuta do espaço sonoro na obra de Cildo Meireles

Esta pesquisa estuda a escuta de um espaço sonoro na obra do artista brasileiro Cildo Meireles. Para tanto, investiga a utilização do som na obra do artista e sua emissão em seis trabalhos, a saber: Mebs/Caraxia (1970-1971), Sal sem carne (1975), Rio Oir (1976-2011), em que o suporte principal é o objeto disco de vinil; Babel (2001-2006) e Liverbeatlespool (2004), nos quais o objeto rádio é responsável pela emissão do som, ou inserção memorial e histórica de uma sonoridade; e Através (1983-1989), cujo emissor é o espectador que atravessa a instalação. Descreve-se aqui criticamente cada um dos trabalhos, considerando-se a existência de um espaço sonoro, e pesquisa-se a fruição do espectador no encontro com as obras. O trabalho também mostra um ponto de contato com o uso do disco de vinil, estabelecendo aproximações e distanciamentos da escuta musical e da escuta dos sons. Articula o som, como efeito físico, com os campos sonoros da obra de Cildo Meireles, relacionando-o com as elaborações, imagens, personagens da ficção ou da história aos quais o artista recorre em sua produção. A pesquisa caminha em direção à escuta, levando à acuidade dessa escuta, considerando a proposta de uma sonoridade que demanda uma escuta autoral. Palavras-Chaves: Cildo Meireles, arte contemporânea, som, escuta, espaço