title: Ultracold lattice gases with periodically modulated interactions.
abstract: We show that a time-dependent magnetic field inducing a periodically modulated scattering length may lead to interesting novel scenarios for cold gases in optical lattices, characterized by a nonlinear hopping depending on the number difference at neighboring sites. We discuss the rich physics introduced by this hopping, including pair superfluidity, exactly defect-free Mott-insulator states for finite hopping, and pure holon and doublon superfluids. We also address experimental detection, showing that the introduced nonlinear hopping may lead in harmonically trapped gases to abrupt drops in the density profile marking the interface between different superfluid regions.
authors.affiliation: Institut für Theoretische Physik, Leibniz Universität, 30167 Hannover, Germany.
authors.forename: Ákos
authors.initials: Á
authors.lastname: Rapp
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Deng
authors.forename: Luis
authors.initials: L
authors.lastname: Santos