Printable organic and inorganic materials for flexible electrochemical devices

Portuguese Science Foundation - project Electra PTDC/CTM/099124/2008 and the PhD grant SFRH/BD/45224. financial support: Professor E. Fortunato’s ERC 2008 Advanced Grant (INVISIBLE contract number 228144), “APPLE” FP7-NMP-2010-SME/262782-2 and “SMARTEC” FP7-ICT-2009.3.9/25820

From contextuality of a single photon to realism of an electromagnetic wave

Violations of Bell inequalities have been an incontestable indicator of non-classicality since the seminal paper by John Bell. However, recent claims of Bell inequalities violations with classical light have cast some doubts on their significance as hallmarks of non-classicality. Here, we challenge those claims. The crux of the problem is that such classical experiments simulate quantum probabilities with intensities of classical fields. However, fields intensities measurements are radically different from single-photon detections, which are primitives of any genuine Bell experiment. We show that this fundamental difference between field intensities measurements and single photon detections shifts the classical bound of relevant Bell inequalities to its algebraic limit, leaving no place for their violations.Comment: 11 pages, 4 figure

Single Scale for Odor Intensity in Rat Olfaction

SummaryHumans and laboratory animals are thought to discriminate sensory objects using elemental perceptual features computed by neural circuits in the brain [1, 2]. However, it is often difficult to identify the perceptual features that animals use to make specific comparisons. In olfaction, changes in the concentration of a given odor lead to discriminable changes in both its perceived quality [3, 4] and intensity [5, 6]. Humans use perceived intensity to compare quantities of different odors. Here we establish that laboratory rats also use perceived intensity to compare concentrations of different odors and reveal the perceptual organization of this elemental feature. We first trained rats to classify concentrations of single odors as high or low. When subsequently classifying concentrations of two odors presented on different trials of the same session, rats made errors consistent with using a single intensity criterion for both odors. This allowed us to investigate the relative perceived intensity of different odor pairs. Odor intensity was not only a function of concentration, but varied also with molecular weight and exposure time. These findings demonstrate the role of perceived intensity as an elemental perceptual feature of odors in rat olfaction

Unmodulated spin chains as universal quantum wires

We study a quantum state transfer between two qubits interacting with the ends of a quantum wire consisting of linearly arranged spins coupled by an excitation conserving, time-independent Hamiltonian. We show that if we control the coupling between the source and the destination qubits and the ends of the wire, the evolution of the system can lead to an almost perfect transfer even in the case in which all nearest-neighbour couplings between the internal spins of the wire are equal.Comment: 4 pages, 5 figure

Trapping a particle of a quantum walk on the line

We observe that changing a phase at a single point in a discrete quantum walk results in a rather surprising localization effect. For certain values of this phase change the possibility of localization strongly depends on the internal coin-state of the walker.Comment: 5 pages, 4 figure