Collective modes of a strongly interacting Bose gas: probing the Mott transition

We analyze the collective modes of a harmonically trapped, strongly interacting Bose gas in an optical lattice in the vicinity of the Mott insulator transition. For that aim we employ the dynamical Gutzwiller equations, by performing real-time evolution and by solving the equations in linear response. We find a strong dependence on the spatial dimension of the system: while in one dimension the frequency of the dipole mode vanishes at the Mott transition, in higher dimensions the dominant dipole mode is featureless and we find a signature only in the breathing mode. We discuss implications for experiments with bosonic and fermionic atoms.Comment: 10 pages, 7 figures; updated figures, published versio

Microscopic Wave Functions of Spin Singlet and Nematic Mott States of Spin-One Bosons in High Dimensional Bipartite Lattices

We present microscopic wave functions of spin singlet Mott insulating states and nematic Mott insulating states. We also investigate quantum phase transitions between the spin singlet Mott phase and the nematic Mott phase in both large-N limit and small-N limit (N being the number of particles per site) in high dimensional bipartite lattices. In the mean field approximation employed in this article we find that phase transitions are generally weakly first order.Comment: 8 pages, 6 figures; final version, to appear in PR

Deliverable 5.2 Study report on consumer motivations and behaviours for fruits and fruit products in the Balkans

It is unclear whether fruit consumption in Western Balkan countries (WBC) meets recommended levels from a health perspective. A better understanding consumers' perception of health and motives and barriers of fruit is necessary to get insight in the fruit consumption. The aim of WP 5 is therefore to explore, analyze and understand perceptions, motivations and barriers of consumers in WBC towards fruit and fruit products and their nutritional balance. In this WP 5 the focus is on consumption of fruit in everyday life, which means that fresh fruit as well as dried and processed fruit are studied

Magnetic phases of two-component ultracold bosons in an optical lattice

We investigate spin-order of ultracold bosons in an optical lattice by means of Dynamical Mean-Field Theory. A rich phase diagram with anisotropic magnetic order is found, both for the ground state and at finite temperatures. Within the Mott insulator, a ferromagnetic to antiferromagnetic transition can be tuned using a spin-dependent optical lattice. In addition we find a supersolid phase, in which superfluidity coexists with antiferromagnetic spin order. We present detailed phase diagrams at finite temperature for the experimentally realized heteronuclear 87Rb - 41K mixture in a three-dimensional optical lattice.Comment: 6 pages, 4 figures, revised and published versio