Simulating and detecting artificial magnetic fields in trapped atoms

A Bose-Einstein condensate exhibiting a nontrivial phase induces an artificial magnetic field in immersed impurity atoms trapped in a stationary, ring-shaped optical lattice. We present an effective Hamiltonian for the impurities for two condensate setups: the condensate in a rotating ring and in an excited rotational state in a stationary ring. We use Bogoliubov theory to derive analytical formulas for the induced artificial magnetic field and the hopping amplitude in the limit of low condensate temperature where the impurity dynamics is coherent. As methods for observing the artificial magnetic field we discuss time of flight imaging and mass current measurements. Moreover, we compare the analytical results of the effective model to numerical results of a corresponding two-species Bose-Hubbard model. We also study numerically the clustering properties of the impurities and the quantum chaotic behavior of the two-species Bose-Hubbard model.Comment: 14 pages, 9 figures. Published versio

Inflation and Growth: New Evidence From a Dynamic Panel Threshold Analysis

We introduce a dynamic panel threshold model to shed new light on the impact of inflation on long-term economic growth. The empirical analysis is based on a large panel-data set including 124 countries during the period from 1950 to 2004. For industrialized countries, our results confirm the inflation targets of about 2% set by many central banks. For non-industrialized countries, we estimate that inflation hampers growth if it exceeds 17%. Below this threshold, however, the impact of inflation on growth remains insignificant. Therefore, our results do not support growth-enhancing effects of inflation in developing countries.Inflation Thresholds, Inflation and Growth, Dynamic Panel Threshold Model