Novel techniques for a Strontium Optical Lattice Clock

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Economic Growth and the Public Sector: A Comparison of Canada and Italy, 1870-2013

There is considerable evidence that the size of the public sector can influence an economy’s rate of economic growth. We investigate public sector spending of central governments and economic performance in two G7 countries over the long-term, Canada and Italy. Their economic performance has diverged in the last 25 years and it is worth investigating whether the size of government was a contributing factor. We find that in both the case of Canada and Italy the size of central government spending directly affects the performance of their economies in an inverse U-shaped relationship known as a Scully/BARS Curve. These results suggest that along with modifying current central government size, other levels of governments may need to shrink their own spending. The fact that the amount spent by government on pensions as a percentage of GDP in Italy is nearly 4 times that in Canada may partly explain the higher level of Italy’s public debt as well as an indirect contributing factor to economic stagnation in the last 25 years

Spend Less, Get More? Explaining Health Spending and Outcome Differences Between Canada and Italy

Canada spends more than Italy on health per capita and as a share of GDP and has a higher per capita GDP.  Yet, life expectancy and infant mortality in Italy are better and have improved more over time.  The implication is that the Italian health care system provides better value for money.  We examine whether Italy does get better health outcomes at lower costs. Using regression analysis, we find that health spending is determined by similar drivers in both Canada and Italy.  We also find that more social spending and health spending in either country do not satisfactorily explain the differences in health outcomes, suggesting the importance of broader socio-economic determinants like income and life-style choices.  We conclude that while the levels of per capita health spending in Canada are higher than Italy, this partly reflects historical inertia in Canadian health spending partially attributable to the higher costs of health professionals relative to Italy

Optically loaded Strontium lattice clock with a single multi-wavelength reference cavity

We report on the realization of a new compact strontium optical clock using a 2-D magneto-optical-trap (2D-MOT) as cold atomic source and a multi-wavelength cavity as the frequency stabilization system. All needed optical frequencies are stabilized to a zero-thermal expansion high-finesse optical resonator and can be operated without frequency adjustments for weeks. We present the complete characterization of the apparatus. Optical control of the atomic source allows us to perform low-noise clock operation without atomic signal normalization. Long- and short-term stability tests of the clock have been performed for the 88 Sr bosonic isotope by means of interleaved clock operation. Finally, we present the first preliminary accuracy budget of the system

Dynamics and interaction of vortex lines in an elongated Bose-Einstein condensate

We study the real-time dynamics of vortex lines in a large elongated Bose-Einstein condensate (BEC) of sodium atoms using a stroboscopic technique. Vortices are spontaneously produced via the Kibble-Zurek mechanism in a quench across the BEC transition and then they slowly precess keeping their orientation perpendicular to the long axis of the trap as expected for solitonic vortices in a highly anisotropic condensate. Good agreement with theoretical predictions is found for the precession period as a function of the orbit amplitude and the number of condensed atoms. In configurations with two or more vortex lines, we see signatures of vortex-vortex interaction in the shape and visibility of the orbits. In addition, when more than two vortices are present, their decay is faster than the thermal decay observed for one or two vortices. The possible role of vortex reconnection processes is discussed.Comment: 4 pages, 4 figure

Production of large Bose-Einstein condensates in a magnetic-shield-compatible hybrid trap

We describe the production of large ${}^{23} \mathrm{Na}$ Bose-Einstein condensates in a hybrid trap characterized by a weak magnetic field quadrupole and a tightly focused infrared beam. The use of small magnetic field gradients makes the trap compatible with the state-of-the-art magnetic shields. By taking advantage of the deep cooling and high efficiency of gray molasses to improve the initial trap loading conditions, we produce condensates composed of as much as $7$ million atoms in less than $30 \; \mathrm{s}$.Comment: 8 pages, 3 figure

Cold atoms meet lattice gauge theory

The central idea of this review is to consider quantum field theory models relevant for particle physics and replace the fermionic matter in these models by a bosonic one. This is mostly motivated by the fact that bosons are more ‘accessible’ and easier to manipulate for experimentalists, but this ‘substitution’ also leads to new physics and novel phenomena. It allows us to gain new information about among other things confinement and the dynamics of the deconfinement transition. We will thus consider bosons in dynamical lattices corresponding to the bosonic Schwinger or Z2 Bose–Hubbard models. Another central idea of this review concerns atomic simulators of paradigmatic models of particle physics theory such as the Creutz–Hubbard ladder, or Gross–Neveu–Wilson and Wilson–Hubbard models. This article is not a general review of the rapidly growing field—it reviews activities related to quantum simulations for lattice field theories performed by the Quantum Optics Theory group at ICFO and their collaborators from 19 institutions all over the world. Finally, we will briefly describe our efforts to design experimentally friendly simulators of these and other models relevant for particle physics. This article is part of the theme issue ‘Quantum technologies in particle physics’