Many-body physics with Ytterbium Fermi gases in optical lattices: from one-dimensional systems to orbital magnetism

Ultracold atoms provide a powerful platform to address fundamental problems in manybody quantum physics. Owing to their rich electronic structure, ultracold two-electron atoms o er new exciting possibilities, enlarging the range of physical phenomena that it is possible to investigate with these atomic systems. This thesis reports on the experimental investigation of ultracold fermionic Ytterbium atoms in optical lattices. These alkaline-earth-like atoms are characterized by purely nuclear spin, completely decoupled from the electronic degrees of freedom. Consequently their low-energy scattering properties are independent of the nuclear spin orientation, giving rise to a SU(N) symmetry class, where N is the number of nuclear spin components. These features allowed us to demonstrate the rst experimental realization of onedimensional quantum gases of ultracold fermions interacting within the SU(N) symmetry class, where N can be adjusted from 2 to 6. The ndings of this work are interpretable in the framework of the Tomonaga-Luttinger liquid model, which is the paradigmatic description for one-dimensional interacting quantum systems. By tuning the number of spin components, we observed that the static and dynamic properties of the system deviate from those of ideal fermions and, for N > 2, from those of a spin-1=2 Luttinger liquid. In particular, we validated for the rst time the prediction that, in the large-N limit, one-dimensional Fermi gas exhibits properties of a bosonic spinless liquid. All the experimental results have been enabled by the construction of a versatile setup that makes possible the manipulation of atomic clouds of fermionic 173Yb in optical lattices as well as the optical detection and accurate control of the number of nuclear spin components by means of optical pumping processes. Moreover, atomic Ytterbium provides the possibility to engineer coherent Raman couplings between di erent nuclear spin states. By studying and implementing such Raman processes, we paved the way to the investigation of spin-orbit physics and arti cial gauge elds with multi-component fermions. In addition to their nuclear spin, two-electron fermions o er experimental access to long-lived electronically-excited states. Coherent control of Ytterbium clock transition 1S0 ! 3P0 in three-dimensional optical lattices has led to the rst observation of fast, coherent spin-exchange oscillations between two 173Yb atoms in di erent electronic orbitals. These experiments show that two-electrons atoms in optical lattices can be used as novel quantum simulators of unique many-body phenomena such as SU(N) orbital magnetism

Physically based approaches incorporating evaporation for early warning predictions of rainfall-induced landslides

Abstract. In the field of rainfall-induced landslides on sloping covers, models for early warning predictions require an adequate trade-off between two aspects: prediction accuracy and timeliness. When a cover's initial hydrological state is a determining factor in triggering landslides, taking evaporative losses into account (or not) could significantly affect both aspects. This study evaluates the performance of three physically based predictive models, converting precipitation and evaporative fluxes into hydrological variables useful in assessing slope safety conditions. Two of the models incorporate evaporation, with one representing evaporation as both a boundary and internal phenomenon, and the other only a boundary phenomenon. The third model totally disregards evaporation. Model performances are assessed by analysing a well-documented case study involving a 2 m thick sloping volcanic cover. The large amount of monitoring data collected for the soil involved in the case study, reconstituted in a suitably equipped lysimeter, makes it possible to propose procedures for calibrating and validating the parameters of the models. All predictions indicate a hydrological singularity at the landslide time (alarm). A comparison of the models' predictions also indicates that the greater the complexity and completeness of the model, the lower the number of predicted hydrological singularities when no landslides occur (false alarms)

A compact ultranarrow high-power laser system for experiments with 578nm Ytterbium clock transition

In this paper we present the realization of a compact, high-power laser system able to excite the Ytterbium clock transition at 578 nm. Starting from an external-cavity laser based on a quantum dot chip at 1156 nm with an intra-cavity electro-optic modulator, we were able to obtain up to 60 mW of visible light at 578 nm via frequency doubling. The laser is locked with a 500 kHz bandwidth to a ultra-low-expansion glass cavity stabilized at its zero coefficient of thermal expansion temperature through an original thermal insulation and correction system. This laser allowed the observation of the clock transition in fermionic $^{173}$Yb with a < 50 Hz linewidth over 5 minutes, limited only by a residual frequency drift of some 0.1 Hz/s

Two Applications of Soil Water Balance in Unsaturated Pyroclastic Soils

Abstract Evaluation of the monthly soil water balance (SWB) provides a tool for understanding and predicting the effects of seasonal and long-term changes in soil water conditions within many geotechnical problems. In this paper, two applications of the SWB approach in the pyroclastic partially saturated soils are shown. Firstly, rainfall, evapotranspiration, water storage measured or estimated at the experimental site in Monteforte Irpino (in Southern Italy) are shown. Secondly, rainfall, infiltration, actual evapotranspiration and water storage measured by data provided by a physical model are shown. In the both cases, data are reported over two years (2010-2012). The physical model was constituted by a wooden tank filled with reconstituted silty pyroclastic soil taken from experimental site at Monteforte Irpino (AV) and it was exposed to the atmosphere at a site in Napoli. Comparison between soil hydraulic behaviours observed is discussed and the scale effects on the estimation of the SWB are analysed, treating with practical implications. From the results, it is clear that similar trends in SWB and the same value of suction over wet season (10 kPa) can be observed at both the scales in spite of differences in meteorological conditions and hydraulic properties of soils exposed to atmosphere

Biological effects of Cannabidiol on normal human healthy cell populations: Systematic review of the literature.

A systematic review was performed to evaluate the biological effects of Cannabidiol (CBD), one of the major components of Cannabis Sativa, on normal human healthy cell populations in terms of cell viability, proliferation, migration, apoptosis and inflammation. Inclusion criteria were: studies on cell lines and primary cell culture from healthy donors, CBD exposure as variable, no CBD exposure as control and published in English language. Quality assessment was based on ToxR tool, with a score of reliability ranging from 15 to 18.Following the PRISMA statement, three independent reviewers performed both a manual and an electronic search using MEDLINE via PubMed, Scopus, Web of Science and Cochrane. From a total of 9437eligible articles, 29 studies have been selected. The average quality assessment score was 16.48.Theresults showed heterogeneous CBD concentration exposure (0.01-50 μM or 0.1 nmol/mL-15 mg/mL). The definition of a threshold limit would allow the identification of specific effects on expected outcomes. From the data obtained CBD resulted to inhibit cell viability in a dose-dependent manner above 2 μM, while in oral cell populations the inhibitory concentration is higher than 10 μM. Moreover, it was observed a significantly inhibition of cell migration and proliferation. On the contrary, it was highlighted a stimulation of apoptosis only at high doses (from 10 μM).Finally, CBD produced an anti-inflammatory effect, with a reduction of the pro-inflammatory cytokine gene expression and secretion. CBD down-regulated ROS production, although at high concentrations (16 μM) increased ROS-related genes expression. The diffusion of CBD for therapeutic and recreational uses require a precise definition of its potential biological effects. A thorough knowledge of these aspects would allow a safe use of this substance without any possible side effects