3 research outputs found
Against Chaos in Temperature in Mean-Field Spin-Glass Models
We study the problem of chaos in temperature in some mean-field spin-glass
models by means of a replica computation over a model of coupled systems. We
propose a set of solutions of the saddle point equations which are
intrinsically non-chaotic and solve a general problem regarding the consistency
of their structure. These solutions are relevant in the case of uncoupled
systems too, therefore they imply a non-trivial overlap distribution
between systems at different temperatures. The existence of such
solutions is checked to fifth order in an expansion near the critical
temperature through highly non-trivial cancellations, while it is proved that a
dangerous set of such cancellations holds exactly at all orders in the
Sherrington-Kirkpatrick (SK) model. The SK model with soft-spin distribution is
also considered obtaining analogous results. Previous analytical results are
discussed.Comment: 20 pages, submitted to J.Phys.
Disordered ultracold atomic gases in optical lattices: A case study of Fermi-Bose mixtures
We present a review of properties of ultracold atomic Fermi-Bose mixtures in
inhomogeneous and random optical lattices. In the strong interacting limit and
at very low temperatures, fermions form, together with bosons or bosonic holes,
{\it composite fermions}. Composite fermions behave as a spinless interacting
Fermi gas, and in the presence of local disorder they interact via random
couplings and feel effective random local potential. This opens a wide variety
of possibilities of realizing various kinds of ultracold quantum disordered
systems. In this paper we review these possibilities, discuss the accessible
quantum disordered phases, and methods for their detection. The discussed
quantum phases include Fermi glasses, quantum spin glasses, "dirty"
superfluids, disordered metallic phases, and phases involving quantum
percolation.Comment: 29 pages and 11 figure