Walter Hofstetter

TL;DR: In this article, the authors describe an atomic physics experiment that can provide critical insight into the origin of high-temperature superconductivity in cuprates, using standing wave light.

Abstract: We present a theoretical analysis of the phase diagram of two- component bosons on an optical lattice. An ew formalism is developed which treats the effective spin interactions in th eM ott and superfluid phases on the same footing. Using this new approach we chart the phase boundaries of the broken spin symmetry states up to the Mott to superfluid transition and beyond. Near the transition point, the magnitude of spin exchange can be very large, which facilitates the experimental realization of spin-ordered states. We find that spin and quantum fluctuations have a dramatic effect on the transition, making it first order in extended regions of the phase diagram. When each species is at integer filling, an additional phase transition may occur, from a spin-ordered insulator to aM ott insulator with no broken symmetries. We determine the phase boundaries in this regime and show that this is essentially a Mott transition in the spin sector.

TL;DR: Using the Keldysh formalism, the Friedel sum rule, and the numerical renormalization group, the exact zero-temperature linear conductance G is calculated as a function of the AB phase phi and level position epsilon.

TL;DR: This work investigates the fermionic SU(N) Hubbard model on the two-dimensional square lattice for weak to moderate interactions using renormalization group and mean-field methods and results may be relevant to future experiments with cold fermion atoms in optical lattices.

TL;DR: The phase diagram of correlated, disordered electron systems is calculated within dynamical mean-field theory using the geometrically averaged ("typical") local density of states.