Abstract:
The interplay between interaction and inhomogeneity for electrons in solids generates many interesting phenomena, including insulating and metallic behavior, magnetism, superconductivity, quantum criticality, and more exotic phases. Many of the same phenomena appear in ultra-cold fermionic atoms in optical lattices which provide clean, controlled, and widely tunable “quantum simulators” to explore the intriguing physics of fermionic systems. While density functional theory (DFT) is widely used as a powerful standard tool for the calculation of material properties, it has not yet been applied to cold atomic gases in optical lattices. Here we present a new density functional for short-range interactions (as opposed to Coulomb interactions of electrons), which allows to use DFT for atomic Fermi gases. This lets us access an extensive toolset, already well developed for materials simulations, to calculate the static and dynamic properties of atomic Fermi gases in optical lattices and external potentials. In return one can use ultra-cold atom quantum simulators to explore limitations of DFT functionals and to further improve hybrid functionals, thus forming a new strong bridge between materials simulation and atomic physics.
Coffee and tea will be served 20 minutes prior to the seminar.