Local Thermodynamical Stability of Fermion Lattice Systems

Huzihiro Araki, Geoffrey L. Sewell

Geoffrey L. Sewell

Akihisa Koga, Takuji Higashiyama, Kensuke Inaba +2 more

We study ultracold fermionic atoms loaded in an optical lattice with a confining potential. By combining dynamical mean-field approximation with a two-site impurity solver, we demonstrate that a supersolid state, where an s -wave superfluid coexists with a density-wave state of checkerboard pattern, is stabilized by attractive onsite interactions on a square lattice. The stability of the supersolid state in the thermodynamic limit is also addressed.

Zygmunt M. Galasiewicz

Karol Makuch, Jan Skolimowski, P B Chakraborty +2 more

Motivated by the rapidly growing possibilities for experiments with ultracold atoms in optical lattices, we investigate the thermodynamic properties of correlated lattice fermions in the presence of an external spin-dependent random potential. The corresponding model, a Hubbard model with spin-dependent local random potentials, is solved within dynamical mean-field theory. This allows us to present a comprehensive picture of the thermodynamic properties of this system. In particular, we show that for a fixed total number of fermions spin-dependent disorder induces a magnetic polarization. The magnetic response of the polarized system differs from that of a system with conventional disorder.

Hans A. De Raedt, Ad Lagendijk