Generalization of short coherent control pulses: extension to arbitrary rotations

We generalize the problem of the coherent control of small quantum systems to the case where the quantum bit (qubit) is subject to a fully general rotation. Following the ideas developed in Pasini et al (2008 Phys. Rev. A 77, 032315), the systematic expansion in the shortness of the pulse is extended to the case where the pulse acts on the qubit as a general rotation around an axis of rotation varying in time. The leading and the next-leading corrections are computed. For certain pulses we prove that the general rotation does not improve on the simpler rotation with fixed axis.Comment: 6 pages, no figures; published versio

Paesaggio sacralizzato e militanza ecclesiale

Il contributo focalizza il tema della sacralizzazione del paesaggio nella contemporanità, ponendo la questione in relazione con le dinamiche storico-sociali e politiche del Dopoguerra. Caso-studio è il Getsemani di Casale Corte Cerro, ideato da Luigi Gedda - protagonista della politica italiana degli anni Cinquanta - e realizzato da Ildo Avetta

Optimization of Short Coherent Control Pulses

The coherent control of small quantum system is considered. For a two-level system coupled to an arbitrary bath we consider a pulse of finite duration. We derive the leading and the next-leading order corrections to the evolution operator due to the non-commutation of the pulse and the bath Hamiltonian. The conditions are computed that make the leading corrections vanish. The pulse shapes optimized in this way are given for $\pi$ and $\frac{\pi}{2}$ pulses.Comment: 9 pages, 6 figures; published versio

Hidden order in bosonic gases confined in one dimensional optical lattices

We analyze the effective Hamiltonian arising from a suitable power series expansion of the overlap integrals of Wannier functions for confined bosonic atoms in a 1d optical lattice. For certain constraints between the coupling constants, we construct an explicit relation between such an effective bosonic Hamiltonian and the integrable spin-$S$ anisotropic Heisenberg model. Therefore the former results to be integrable by construction. The field theory is governed by an anisotropic non linear $\sigma$-model with singlet and triplet massive excitations; such a result holds also in the generic non-integrable cases. The criticality of the bosonic system is investigated. The schematic phase diagram is drawn. Our study is shedding light on the hidden symmetry of the Haldane type for one dimensional bosons.Comment: 5 pages; 1 eps figure. Revised version, to be published in New. J. Phy

Trichocline maxima (Compositae, Mutisieae) a rare Pampean daisy rediscovered after 70 years in Uruguay

Trichocline maxima was considered probably extinct but has been rediscovered in northern Uruguay after almost 70 years since its last record in this country. We provide an updated description of the species, an indication of a lectotype and we discuss morphology, taxonomy, nomenclature, geographical distribution, and conservation status of the species. An identification key for the species of the genus in Uruguay and Brazil is also presented.Trichocline maxima (Compositae, Mutisieae) redescoberta: Taxonomia, lectotipificação, e estado de conservação de uma Asteraceae rara e endêmica do Pampa. Trichocline maxima era considerada como provavelmente extinta, mas foi redescoberta no norte do Uruguai após quase 70 anos desde sua última coleta neste país. Neste trabalho são fornecidas descrição atualizada da espécie, a indicação de um lectótipo e discussão sobre aspectos morfológicos, taxonômicos, nomenclaturais, de distribuição geográfica e estado de conservação. Também é presentada uma chave de identificação para as espécies do gênero no Uruguai e no Brasil

Protein Microdeposition Using a Conventional Ink-Jet Printer

Many recent bioanalytical systems based on immunologic and hybridization reactions in a mono- or bidimensional microarray format require technology that can produce arrays of spots containing biospecific molecules. Some microarray deposition instruments are commercially available, and other devices have been described in recent papers. We describe a system obtained by adapting a commercial ink-jet printer and used to produce mono- and bidimensional arrays of spots containing horseradish peroxidase on cellulose paper. In a few minutes, it was possible to obtain bidimensional arrays containing several thousands of spots with a diameter as low as 0.2 mm, with each of which requiring only a few nanoliters of the enzyme deposition solution. The quantity of enzyme in each spot was evaluated with a chemiluminescent reaction and a charge-coupled device-based, low-light imaging luminograph. The chemiluminescence measurements revealed that the reproducibility of the enzyme deposition was satisfactory for analytical purposes, with the variation coefficients being lower than 10% in almost all cases

Attribution of recent temperature behaviour reassessed by a neural-network method

Abstract Attribution studies on recent global warming by Global Climate Model (GCM) ensembles converge in showing the fundamental role of anthropogenic forcings as primary drivers of temperature in the last half century. However, despite their differences, all these models pertain to the same dynamical approach and come from a common ancestor, so that their very similar results in attribution studies are not surprising and cannot be considered as a clear proof of robustness of the results themselves. Thus, here we adopt a completely different, non-dynamical, data-driven and fully nonlinear approach to the attribution problem. By means of neural network (NN) modelling, and analysing the last 160 years, we perform attribution experiments and find that the strong increase in global temperature of the last half century may be attributed basically to anthropogenic forcings (with details on their specific contributions), while the Sun considerably influences the period 1910–1975. Furthermore, the role of sulphate aerosols and Atlantic Multidecadal Oscillation for better catching interannual to decadal temperature variability is clarified. Sensitivity analyses to forcing changes are also performed. The NN outcomes both corroborate our previous knowledge from GCMs and give new insight into the relative contributions of external forcings and internal variability to climate