title: Discerning incompressible and compressible phases of cold atoms in optical lattices.
abstract: Experiments with cold atoms trapped in optical lattices offer the potential to realize a variety of novel phases but suffer from severe spatial inhomogeneity that can obscure signatures of new phases of matter and phase boundaries. We use a high temperature series expansion to show that compressibility in the core of a trapped Fermi-Hubbard system is related to measurements of changes in double occupancy. This core compressibility filters out edge effects, offering a direct probe of compressibility independent of inhomogeneity. A comparison with experiments is made.
authors.affiliation: Department of Chemistry and Pitzer Center for Theoretical Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: V W
authors.initials: VW
authors.lastname: Scarola
authors.forename: L
authors.initials: L
authors.lastname: Pollet
authors.forename: J
authors.initials: J
authors.lastname: Oitmaa
authors.forename: M
authors.initials: M
authors.lastname: Troyer